Keeping The Water Warm

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► Heater Operating Costs?

Living in the Daytona area of Florida, I just had an inground fiberglass pool installed and love it. I'm wondering about how much a year it would cost to run a natural gas heater. It is a 12' x 28' X 4.5 ft. deep pool. Thank you for any info or suggestions.

Christopher R., Florida, 9/28/2008

I don't have access to that type of information.  You should direct the question to the local gas supplier or a gas heater contractor.  In addition to the cost of natural gas and where, in the country,  you are located the individual factors of pool exposure, desired water temperature and whether or not a cover will be used have to be considered.  An automatic safety cover can reduce heater costs by up to 70%.  A gas heater may not be the most economical - check into a heat pump.  Heating costs can be reduced or controlled by employing a pool automation device.  Want a FREE source of heat?  A Solar Pool Heating System can run off your existing filtration system pump and can raise the water temperature up to 10ºF.  Good luck and I hope that I have been helpful.

Sincerely.  Alan Schuster, 9/28/2008

► Heat Pump Practicality?

I am looking into adding a heater to my inground pool.  I see a lot of material concerning heat pumps.  Are they really practical for pools.  I live in Vero Beach, Florida.  Thank you.

Barbara F., Vero Beach, FL, 8/13/2004

As a matter of fact, heat pumps are very practical, especially in the sunbelt.  In your location it should work out very well.  There is a practical, if not physical limit, as to how much a heat pump can do in terms of raising the temperature.  Check to see what that limit is and consider if you want to use the pool all year.  It wouldn't be practical for year round use in New York, for example.  In New York it performs very well during the normal season and would be well suited towards extending both ends of the typical swimming season.  In your area, it should be able to perform virtually all year.   But, check it out to make sure before committing to a purchase.  If you are interested in reducing operating costs, you might consider using a pool safety cover.  These cover reduce evaporation, keep the heat in and provide safety for animals and kids.  But, check it out to make sure before committing to a purchase.  Good luck and I hope that I was helpful.

Sincerely.  Alan Schuster, 8/13/2004

► Efficiency Concerns?

What is the most efficient way to run a pool heater in South Florida?   Is it more economical to turn off the heater at night? Or should it be simply lowered or kept at the temperature for swimming.  Also what is the recommended temperature to heat a pool?  We can't agree.  I like it at 87 to 90. He likes it at 82 to 84.  We do not have a solar/pool blanket.  Would this help by keeping the temperature up?  Also how long does it take to heat up the water. if it's turned off every night w/o a pool blanket?  If we do get a solar pool blanket, how can it easily be taken on & off?  Thanks.

Bev, Florida, 12/22/2008

Lots of questions.  Unfortunately, they all don't have answers.  Most heaters and filtering systems are not run 24/7.  Heating the water for the overnight period, only increases the heat loss.  I would shut the heater down prior to the last use of the pool and start the cycle again, a few hours prior to the first use of the day.  The later in the morning - the better.  You might as well have the Sun on your side.  Temperature is an individual matter.  It is what you like!  Maybe even what he likes.  Why not compromise on 85°F?  A solar blanket will positively reduce heating costs.  How long it takes to raise the water 1° will depend upon the heater type, size, water temperature, Sun exposure, wind, etc.  Your heater instruction manual might provide the information.  The water will heat up quicker with a solar blanket on.  A roller system helps make a solar blanket less unwieldy.  The easiest way to cover a pool is with an automatic pool cover.  It can be done at the push of a button.  For more on this product go to www.coverpools.com  I hope that the information proves helpful.

Sincerely.  Alan Schuster, 12/22/2008

► Where Should The Heater Go?

We have an inground pool with an chlorinator (uses 7 oz. tablets) and a DE filter.  The chlorinator is hooked in, just after the filter.  We are planning to add an electric heat pump and are having a dispute as to where it should go.  Can you explain the proper heater placement and settle the dispute.  Feuding in Virginia.

Marty B., Chesepeake, VA, 6/25/2004

There's nothing to argue about!  Put the chlorinator after the heat pump or you could destroy the copper/copper alloy heat exchanger.  The chlorinator must be last in line. The chlorine, in the chlorinator, is acidic in nature and could damage the copper heater core, if placed before the heater.   Placement of the chlorinator at the end will result in warm water passing through the unit.  You may have to throttle back the settings on the chlorinator, in order to slow down the rate of chlorine addition.  This is easier than replacing the heater!   I personally know of someone, that had a heater installed by a plumber (unfamiliar with pools) and he installed it after the chlorinator:  the heater did not last the season!  You should be able to confirm this, by referring to the heater manufacturer's installation instructions.  And don't forget a check valve between the heat pump and the chlorinator.  Information on this can be found in the archives.  Enjoy the warm water.

Sincerely.  Alan Schuster, 6/25/2004

► Do-It-Yourself In-Ground Solar Heating?

We are interested in installing a Do-It-Yourself Solar Heating system for our 16 X 30 inground pool but do not have a lot of money to spend.  Someone told me that we can install a system ourselves by using black tubing and running it around the roof.  Do you have any instructions on how we can do this?

Brenda G., 5/3/2005

In theory, if you ran the line from the filter through a length of black pipe, exposed to Sunlight, it would pick up heat.  Just running pipe around the roof will not create enough surface area to make a meaningful difference.  Solar heater do not just use black pipe - they use thin  cells to increase the surface area, making heat exchange meaningful and efficient.  Doing what you are suggesting will cause you to spend money without much of a return benefit.  That doesn't mean that you can do-it-yourself.  Smartpool offers the Sunheater line of solar pool heaters that can be installed easily by a homeowner.  It utilizes the same pool pump and requires no extra electricity to operate.  The heat produced really is free!  For more information visit:   www.smartpool.com  Enjoy the season and I hope that I have been helpful.

Sincerely.  Alan Schuster, 5/3/2005

► Solar Heating Alternatives?

What a great website! I live on Long Island and we just got a brand new inground pool (16x34). Do have any info on Solar Sun Rings for heating an inground pool? Do they work? Do they work better than a regular solar cover? Thanks so much.

Melissa H., long Island, NY, 6/2/2007

► Above-Ground Solar Heating?

Do the above ground pool solar heaters (like Sunheater) really work and are the worth the money and time to install?  How much do they really raise the temperature?  Thanks for you help.

Bill, 5/19/2009

Solar heat absolutely works!  And even better is the fact that the fuel is free!  With the Sunheater Solar Heating System for above-ground pools, you use the regular pool pump, so there is no additional cost for electricity.  The Sunheater product can be easily installed, by yourself.  A temperature rise of 10 degrees or more can be gained, depending upon weather conditions and location.  With fuel prices going up daily, this may be the only affordable way to heat an above ground pool.  To maximize the benefits of the Sunheater system, operate the pump during daylight hours.  Using a product to retard evaporation, such as the SolarPill, will help retain the higher water temperature.   I hope that this information will make for warmer water.

Sincerely.  Alan Schuster, 5/19/2009

► Economics?

It seems like a Heat-pump type water heater or the salt generator unit, we were thinking of, for an inground system is not so useful for an above ground pool. The cost of the additional systems is way more than the pool itself. Are they worth it?

Martin P., 2/22/2004

It would be difficult to justify spending more on the heat pump, than on the above ground pool.  Heat pumps are very efficient, but how much is warm water worth?  In addition to the purchase cost, there is still the electrical expense.  Why not consider solar heating?  The initial cost can be very modest and, thereafter, it's free!  For more information go to:   www.smartpool.com  Used in conjunction with a solar blanket, it can really make a big difference, depending upon your location and the sunshine level.  A salt chlorination system will help offset the initial cost, by reducing the amount of chemicals needed to maintain proper pool water quality.  Salt chlorinators are convenient and will help keep your pool water in better balance, with less effort.  Both products will make your pool ownership experience more enjoyable!  I hope that the information provided will prove helpful.

Sincerely.  Alan Schuster, 2/22/2004

► Propane Or Natural Gas?

Your website is very helpful, thank you for making it available.  We are in Canada and purchasing a 18'x32' inground straight back kidney pool and I have a few unanswered questions:  Which type of Pool Heater is more efficient? Propane or Natural Gas?  Pros and Cons on each?   Should we get a bottom drain in our pool?  Thank you very much.

Debbie, Canada, 5/16/2006

Natural gas should be more convenient.  Other than the major consideration would be the operating costs and that will depend on local energy costs.  Discuss this with the gas and propane suppliers.  You left out another good choice:  a heat pump.  It operates on electricity and is both clean and convenient.  Again, local energy costs needs to be discussed with the contractor or utility.  Adding an automatic pool safety cover can make a huge difference in heating costs.  A bottom drain will certainly help you keep the pool cleaner and will help to distribute the heat more effectively.  I hope that this information will prove helpful.

Sincerely.  Alan Schuster, 5/16/2006

► Above Ground Solar Heating?

Is solar heating practical for an above ground pool in North Carolina?  Thanks.

Fred H., Fayetteville, NC, 10/2/2003

It is practical and after the initial start up cost it is free.  There are relatively inexpensive do-it-yourself solar pool heaters that can raise the water temperature by as much as 10 degrees F, during ideal weather.  Using with a solar blanket will increase the effectiveness.   I hope that I have been helpful.

Sincerely.  Alan Schuster, 10/2/2003

► Heater Longevity?

Alan, I like your site.  Can you tell me if there is a rule of thumb for how long a pool heater should last?  I have a unit that is about 13 years old.  Thanks!

Sincerely.  Alan Schuster, 3/29/2004

► Heater Corrosion?

We have a 4 yr old gunite pool that when we opened the second year it had a brown ring around it.  It will not come off with scrubbing.  Also, our pool is white plaster that looks light blue now with white scrubbed spots, where it looks bleached out, is this a stain that we can get out.  You also mentioned that you do not like the chlorine tablets in the filter?  What manner of chlorinating do you recommend. Thanks.

Mary, 4/27/2004

To better answer your question, I need to know if you have a heater?

Mary, 4/27/2004

You read that I don't like chlorine tablets in the skimmer.  Unfortunately, now you know why.  Chlorine tablets are acidic and can create the type of chemistry that can slowly destroy the copper heater core.  Based on the presence of the blue coloring on the white plaster and even the brown water line, it seems a virtual certainty that this is the result of copper corrosion.  Copper will dissolve in acidic water that contains chlorine!  Before you do anything else, take the tablets out of the skimmers and add a double dose of a quality metal treatment.  Check the pH and TA.  If you want some confirmation have the water tested for copper.  Hopefully, you may not have destroyed the heater.  If you want to use chlorine tablets, use a feeder that is plumbed inline, after the heater and is separated by a check valve.  If you want a chlorine pool, that will not produce acidic conditions, you should consider a salt chlorinator.  To remove the staining, it may be necessary to lower the pH to about 6.0.  If possible, bypass the heater.  If this is not possible,  add chlorine neutralizer and discharge all of the chlorine.  To help speed up stain removal add a couple of pounds of oxalic or ascorbic acids, keep the filter running and use the scrub brush.  A day or two at these acidic conditions, should make a noticeable difference.  So long as there is no chlorine in the water, the heater is unaffected.  I hope that this information will prove helpful.

Sincerely.  Alan Schuster, 4/27/2004

I live in sunny Yuma AZ.  I am in the process of buying an in ground pool, 14,000 gallons.  How I can heat my pool using the sun's energy?

Jim S., Yuma, AZ 4/26/2008

There are few places, in the U.S., better suited for solar heating.  All that Sun!  Smartpool has a line of Sunheater Solar Heating Products that would be perfect.  It even uses the existing pool pump, so there is no additional electrical cost involved.  Adding The Circulator is an inexpensive accessory, that will help to better distribute the heat and make the temperature more uniform, by eliminating dead zones.  I hope that this helps keep you in warm water.

Sincerely.  Alan Schuster, 4/26/2008

► The Heater Died?

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► Should It Be Replaced?

I just purchased a home with a pool. The pool company has told me that the pool heater and motor have rusted through and to me they looked terrible.  But, how do I know this for sure?  Is there anything that I should particularly be looking for?  Please email me back as soon as possible.  I'd really appreciate it.

Teri W., 4/30/2005

I don't doubt that they look "terrible."  The bottom line is, do they work?  If not, they probably need to be replaced, but I am not sure that that is for me to say.  I am not there to look at it and I am not an expert on this type of equipment.  You don't want to throw good money after bad.  Pumps and heaters do not last forever.  I would hazard a guess that if you replaced the heater with a heat pump, you would realize a huge energy savings over the life of the heater.  Visit www.autopilot.com for information on a quality heat pump.  Pump motors are not the most expensive piece of pool equipment and you might be better off replacing it.  The only other suggestion that I can make is to try and determine the cause of the corrosion and rusting.  Was it poor maintenance, corrosive water chemistry or both?  There is no sense in repeating the past.  Good luck with the pool.

Sincerely.  Alan Schuster, 4/30/2005

► Tablets In The Skimmer?

Just had an inground pool installed with a heater.  We were given a "start up" package of Stabilized quick tabs (dissolve in 15 minutes, providing 59% of available chlorine) and was told by installer that we should use only these tabs daily and place directly in skimmer because of the heater.  I have seen on your site that the slow-dissolving tabs should not be placed in skimmer, but I wondered what other effective chlorinating options I have?  Is a chlorinator the way to go, installed after the heater, or are these quick tabs just as effective?  Thanks.

Chris, 6/2/2003

The product that you are referring to is not slow-dissolving trichlor.  It is a blend of trichlor and soda ash.  This results in a fast dissolving tablet that is relatively neutral.  Placing this type of tablet, in the skimmer, will not have the same negative impact on the heater.  However, if the pool turns acidic, it will have a corrosive effect on the heater.  Adding chlorine through the skimmer is never the best way to add chlorine.  This type of tablet cannot be used in a built-in chlorinator.  Placing these tablets in an enclosed chlorinator could result in a explosion!  Only trichlor tablets can be used in an enclosed chlorinator.  If you want to use an inline chlorinator, you must use trichlor tablets or sticks.  The chlorinator should be last in line, after the heater, and must be installed according to the manufacturer's instructions.  I hope that I have been helpful.

Sincerely.  Alan Schuster, 6/2/2003

► How Can Acid Dissolve Copper?

At the beginning of the season, I had my water tested and amongst other things the dealer found a small amount of copper.  I told him that I never used a copper algaecide.  I only use the Polyquat Type.  Because I have a heater and have a chlorinator with slow-dissolving tablets, he suggested that the copper came from having acidic conditions for a period of time.  The water was treated and no problems resulted.  My question is this.  I'm no chemist, but I remember back in junior high school, we put a penny and a nail in strong acid and only the nail was attacked.  If that is the case, how does acidic swimming pool water dissolve copper in a heater?  Continuing my schooling.  Thanks.

Shelly, B., Stony Brook, NY, 7/2/2004

Some memory.  The teacher must have made a real impression on you.  It is true that a copper penny will not dissolve in acids like hydrochloric or sulfuric, dilute or concentrated.  However, a copper penny will dissolve in acids that are oxidizing agents.  Your teacher might have demonstrated this by placing the penny in a nitric acid solution.  Hypochlorous acid is the active form of chlorine and it is an oxidizing agent.  It, therefore, can and will slowly dissolve copper, if the pH of the pool water drops into the acidic range.   Evidently, for some period of time, the pH in your pool was below 7.0 and this resulted in some heater corrosion.  The chlorine product that you are using will lower the pH, as will acid rain and bathers. This will require regular water testing and pH adjustments.  Your dealer did a good job and probably saved you from a bigger problem.  I hope that today's "lesson" was successful.  Enjoy the season.

Sincerely.  Alan Schuster, 7/2/2004

► pH And Copper Corrosion?

Recently after a new replaster job, it was necessary for the pool contractor to give the finish an acid wash.  We turned off our equipment and they added large doses of Acid that cleaned the pebble plaster.  The pool people returned a second time and added more acid to finish a few places.  After about a week total time they returned the third time and added a bag or so of Soda Ash to raise the pH?  (counter act the acid)  At this time we started the pumps and ran it for a good 6 hours. Then it ran for the next three days as per normal schedule which is about 4 hours a day.  My normal pool person informed me on the fourth day that the acid level was still Very high, well above normal and asked if the acid wash folks had attempted to lower the acid level. I informed him of what had transpired and he mentioned that a very high acid level could damage the heater.  This is a brand new heater that the contractors also installed.  I am hesitant about putting the pumps on at this time and I have sodium bicarbonate in the pool to lower the pH.  A recent check of pH and Chlorine shows continued HIGH pH and NO chlorine. I did read a question on your site regarding a similar instance and you mentioned, for damage to happen to the core of the heater, chlorine or bromine would need to be present.  Along with the new remodel we had a salt system that has been working great and providing the chlorine. However, after several days of no chlorine making, the chlorine level is obviously zero.  Should I feel safe to turn the pumps on and turn the chlorinator off so I can circulate the sodium bicarbonate within the pool and lower the pH?  Thanks.

Mark P., Irvine, CA, 2/23/2005

If the heater core is made of copper or copper alloy, it could be damaged by the presence of chlorine and the maintaining of low pH conditions.  Keeping the pH in the normal 7.2-7.6 range will prevent corrosion of copper parts.  Either you are stating the chemical names incorrectly or you are wasting your time.  Sodium bicarbonate will not lower your pH.  It will raise the total alkalinity and move the pH slightly towards 8.0.  If your pH is too high, you must add acid.  Salt chlorine generators can tend to raise the pH or too much soda ash might have been added.  What you need is acid to optimize the pH!  Before you turn on the chlorinator, I suggest that you add a double dose of a quality metal treatment, in order to help prevent staining, due to metals in the source water of copper corrosion that might have occurred.  I would add another dose monthly or whenever new water is added.  At the very least it will help keep the salt chlorine generator electrode plates cleaner.  Wait a few hours before turning on the chlorinator.  I doubt that any harm was done to the heater.  I hope that I have been helpful.

► Something Other Than Copper?

I recently destroyed my pool heater, as a result of corrosion.  I was putting the 7 oz. tablets in the skimmer and it seems that the copper was corroded by the chlorine.  I am not sure that I want to risk another heater.  How can I avoid risking a repeat?  It was an expensive lesson.   Keeping my cool.

Irving S., Staten Island, NY, 8/2/2004

The copper heater core was not "corroded" by just the chlorine.  It takes the combination of low pH and chlorine to subject copper to corrosion in a swimming pool.  The practice of adding trichlor tablets to the skimmer is not something that I would ever recommend.   Trichlor is very acidic and can slowly lead to corrosive conditions, if the pH is not properly maintained at 7.2-7.8.  Installing an in-line chlorinator, after the heater and last in line, is a better way to add chlorine to the pool.  There are heaters that utilize materials other than copper in the heat exchanger.  Titanium and possibly stainless steel are used in some heaters.  In addition, I believe that there are heaters that contain a chemically inert coating in the heat exchanger.  These materials are less subject to corrosion.  However, for the comfort of bathers and protection of all the metal underwater surfaces, you should maintain a proper pH.  Have you considered solar heating?  In your part of the country, solar heater panels can be used to extend the season.  Solar blankets can be used with all types of heaters, not only to raise or maintain the water temperature, but to reduce operating costs.  I suggest that you discuss heater options with a local pool professional, so far as heater choices and cost considerations.  Good luck with your decision.

Sincerely.  Alan Schuster, 8/2/2004

► Scale Deposits In A Heater?

I read somewhere that very high calcium hardness and pH can lead to scale formation and that scale can form on the underwater surfaces, including in the heater.  My water has over 500 PPM of calcium hardness.  I have a solar heater.  I don't see any real evidence of scale.  Every once in a while, I get cloudy water.  Is there something I can do to avoid a potential problem?  Please help.

J. M., 6/9/2004

A calcium hardness level of 500 PPM can definitely lead to scale formation and it can take place in your solar heater or any other type for that matter.  If so, it will reduce the heater efficiency, by acting as a form of insulation.  Make sure that you keep the pH closer to 7.2, than to 7.6.  Try and lower the total alkalinity to within 80-120 PPM, if practical.  Stop all use of products containing calcium.   Add a quality Mineral Treatment, in order to help sequester the calcium, on a regular basis.  This treatment can actually slowly dissolve scale deposits, over a period of time.  There's nothing in your letter that positively indicates that you have a problem, at this time.   But, some prevention does make sense.  I hope that I have been helpful.

Sincerely.  Alan Schuster, 6/10/2004

► Check Valve?

Should there be a check valve, installed between the natural gas heater and a built-in chlorinator?  Why?  The chlorinator is after the heater and is last in line.  Thanks.

Allen C., Toms River, NJ, 6/4/2003

Absolutely!  When the pump is running the chlorinated water is going into the pool.  When the pump is off, there is a possibility that water might back up from the chlorinator into the heater.  The water in the chlorinator can be quite acidic, due to the nature of the trichlor tablets.  If this water gets into the copper heater core, it will cause corrosion.  Over time, the copper coils can be completely destroyed.  The installation of a check valve will help prevent this from occurring.  All or at least most of the heater manufacturers recommend this type of device.  I hope that I have been helpful.

Sincerely.  Alan Schuster, 6/4/2003

► Check Valve Requirements?

Hi Alan, I have a  gas heater and my heat exchanger just went out a few  weeks ago (green corrosion).  I replaced it. In case this was caused by chlorine, I installed a check valve on the output between the heater and my In-Line chlorinator.  When I installed the check valve. I was unable to install it per the instructions. The instructions say you need 18 inches of up flow after the check valve in order for the weight of the water to keep the check valve closed. As you know, after the water leaves the heater there is not normally an up flow (it is all down flow from there).  After 2 weeks of use, I pulled the return header off and found the new one is turning green on the inside.  I had my water tested and everything was fine except hardness it was a little high (600ppm). But, the tap water in my area is pretty hard so I don't think there is much I can do about that. I doubt the hardness would cause the green corrosion anyway.  So, my conclusion is maybe even though the check valve is spring loaded, it may be allowing the water to seep backwards due to there being a down flow. The only solution I can figure out is, come out of the heater and turn straight up for at least 18 inches. then turn straight down to get to my chlorinator. I don't know if 18 inches of up flow would work followed by an immediate 30 inches of down flow (This seems it might cause it to siphon). This does not seem like a good solution. I would also consider changing out the chlorinator to an off-line system, but I doubt that would help my situation.  Do you have any suggestions.  Thanks so much.

Jamie L., 9/5/2003

The green corrosion is being used by low pH conditions in the presence of chlorine.  If your pool water has not been acidic for extended periods of time, that leaves only the check valve and the backflow from the chlorinator as the possible causes of the problem.  Your solution seems to be workable.  Any siphoning that might be created would direct the water to the pool and that will protect the heater from the corrosive backflow:  the pool water being the lowest point.  The check valve manufacturer's recommendation makes sense for their product and I suggest that you follow them.  I hope that I have been of some assistance. 

Sincerely.  Alan Schuster, 9/6/2003

► Corrosive Causes?

Our inground pool is about 6 years old.  On 7/16/03, a new heat exchanger was installed because of corrosion (water was leaking out of the heater).  On 8/8/03, our water was tested and the pH was 7.4 - perfect.  On 9/4/03, we called the pool company because there was water coming out of our heater again.  They came out on 9/8/03 and replaced the heat exchanger again (cost of $650 - total cost $1300 plus labor).  They tested the water and the pH was 6.8.  The weekend before we had added water to the pool because it was getting a little low.  We were told by the manager of the pool company that the new heat exchanger was damaged because of the pH being low.  My question is, "Can a heat exchanger that was installed on 7/16/03 become so corroded that it needs to be replaced less than two months later?"  A water test in August showed the pH level was fine.   Thanks!

Corrosion is caused by low pH conditions in the presence of chlorine and/or bromine.  In order to maintain a proper pH of 7.2-7.6, it is important to have a total alkalinity of 80-120 or possibly higher.  Certainly not lower than 80 PPM.

Soft water can add to the rate of corrosion.  Check to see that your calcium hardness is 150-200 PPM.  Higher readings will not add to the corrosion problem.

Past experience leads me to suspect that you are using trichlor or bromine tablets in a chlorinator.  These products are quite acidic and will lower the pH.  Their use will probably require regular additions of pH increaser chemical.  Until you get a handle on the situation, I suggest that you test the pH every day.  The chlorinator, if it is built inline, must be placed after the heater and be last in line.  In addition to this many manufacturers recommend that a flow check valve be place between the heater and the chlorinator or brominator.  This prevents the water from the inline feeder from diffusing back into the heater, after the pump is shut off.

I suggest that you check into these possibilities as soon as possible.  In addition, the copper that has been dissolved, should be treated by the addition of a metal treatment.  Add one dose for each 0.5 PPM.  I hope that this information will prove helpful.  Let me know, what you discover.

Sincerely.  Alan Schuster, 9/11/2003

► Copper Corrosion?

After dealing successfully with yellowish stains on the vinyl liner and rigid plastic parts, we had our water chemistry just right except for a small hardness deficit (but stable pH around 7.4 and alkalinity around 110) and we were in business.  Last week, we tired of how cold it was and decided to turn on the three year old heater..  Also this past week, since everything was OK with the water, I set the timer to run the pump 18 hours/day instead of non-stop.  This past Saturday, I realized that the temperature was falling at times because heater was not running reliably and replaced a faulty pressure switch, and this may have been the first time that the heater began to cycle on and off normally.  When mixing chemicals with water to bring our hardness up on Saturday (or MAYBE it was when mixing chlorine to shock; I’m not certain), I noted a brown tinge to the water and thought little of it.  By mid-day Sunday, we realized that the yellowish-brown stains were returning to the liner and the water was taking on a vague aqua color.  A water test at the pool company revealed copper at 0.3 ppm and their suspicion is that poor water maintenance by the previous owners (we just moved in this Spring) caused heat exchanger damage.  I know that the pH has not been below 7.2 since a few weeks ago when I exchanged most of the water to correct a high CYA, followed by chelating agents to remove the severe staining that we started with.  The only thing I can’t prove is that no copper was left behind from the prior treatment. My theory, consistent with your advice elsewhere on your web site, is that the lack of a check valve between the heater and chlorine dispenser is to blame.  (Plumbing is skimmers-pump-DE filter-heater-trichlor dispenser-return.  The chlorinator is about a foot below the heat exchanger; all equipment is at the deck level and therefore the filter outlet and heat exchanger are about 2’ above the water level.)  The heater manufacturer's tech support is surprised that the heater lasted three years without a check valve.  But the pool installer, one of the largest in the area, puts all their heaters in this way without problems, says that they had too much trouble with check valves, and insists that poor water maintenance in the past is by far the most likely culprit.  We’ve never used any algaecides.  My question:  If the copper heat exchanger had sustained damage in the past from acidic water, could it still be putting copper into pH 7.4 water?  Assuming the pool company is correct that relevant back-siphoning of dispenser contents into the heater shouldn’t occur, is it more likely that copper was left behind from the previous chelating treatment?  I did purge the filter as instructed after the treatment.

Nameless, 6/17/2003

The copper could have come from the use, by the previous owners, of products such as copper algaecides or winterizing.  It could have come from corrosion of the heater exchanger, due to acidic conditions.  It could have come from there being no check valve.  The water analysis doesn't prove the source.  If you chelate copper, it doesn't leave the water.  It can remain in the pool water indefinitely, in a stable chelated form.  If you have maintained a pH in the ideal range, recent copper corrosion should not have occurred,  That is if there is a check valve!  The heater works, the pool problems are solved and it is time to enjoy the pool.  Concentrate on what is ahead and don't dwell on the past.  I hope that I have been helpful.

Sincerely.  Alan Schuster, 6/17/2003 

► Check Valve Ups & Downs?

Hi Alan, I have a heater and my heat exchanger just went out a few  weeks ago (green corrosion). I replaced it. Incase this was caused by chlorine, I installed a check valve on the output between the heater and my In-Line chlorinator.  When I installed the check valve. I was unable to install it per the instructions. The instructions say you need 18 inches of up flow after the check valve in order for the weight of the water to keep the check valve closed. As you know, after the water leaves the heater there is not normally an up flow (it is all down flow from there).  After 2 weeks of use, I pulled the return header off and found the new one is turning green on the inside. I had my water tested and everything was fine except hardness it was a little high (600ppm). But, the tap water in my area is pretty hard so I don't think there is much I can do about that. I doubt the hardness would cause the green corrosion anyway. So, my conclusion is maybe even though the check valve is spring loaded, it may be allowing the water to seep backwards due to there being a down flow. The only solution I can figure out is, come out of the heater and turn straight up for at least 18 inches. then turn straight down to get to my chlorinator. I don't know if 18 inches of up flow would work followed by an immediate 30 inches of down flow This seems it might cause it to siphon.  This does not seem like a good solution.  I would also consider changing out the chlorinator to an off-line system, but I doubt that would help my situation.  Do you have any suggestions. Thanks so much.

Jamie L., 9/5/2003

Siphoning is not the issue.  It is a closed loop system and there should be no siphoning.  The issue is making sure that the check valve is closed.  That is the purpose of the 18" inches of water.  The weight of the water will make sure the valve is closed.  Otherwise, there may not be a functioning check valve and the water from the chlorinator - high in chlorine and low in pH - can diffuse into the heater by convection or due to density differences and result in the type of corrosion that you are describing.  That is why a closed check valve is important.  I hope that this clarifies the issue and that the information has been helpful

Sincerely.  Alan Schuster, 9/6/2003

► Solar Heaters?

I live near Hartford CT and am wondering if I can use solar energy to heat my 18,500 gallon inground vinyl pool?  How effective is it?   Many thanks.

John S., 6/20/2004

Solar pool heaters will not keep the water warm enough in your region, much beyond the normal pool opening and closing season.  What it will do is add up to 10ºF to the water temperature during the season and, perhaps, increase your comfort factor.  Using a solar blanket, in conjunction with a solar pool heater, will make even more of a difference in the water temperature.  Once past the initial cost, the big advantage is that it is free!  An alternative to a solar cover is a safety pool cover.  This type of cover can be rolled on or off, manually or automatically and provides safety, reduces water loss and keep in the heat.  Good luck.  I hope that I have been helpful.

Sincerely.  Alan Schuster, 6/20/2004

► Solar Heater Placement?

The home I lived in before I moved to my current home had a solar heating system for the pool  The "collectors" were black PVC pipes set on a cement pad in the corner of our acre+ property.  It was very good - to the point where we had to shut it down in the summer because the pool got too hot!  I am now currently considering the same type of solar heating for my current home in Vero Beach, Florida.  Can the "collectors" be placed on a black-top or cement pad in the corner of our acre property?  The pad would be in the northwest corner with sun available the entire day.  There are no trees or house structures in the area.  We have a metal roof and do not want to fasten any type of solar collector to this roof.  Thanks for your help!  Regards!

Dana C., Vero Beach, Florida, 5/16/2004

Solar panels do not have to be placed on the roof.  In many instances, it is just a convenient location that does not consume backyard space.  Solar panels can be located on or near ground level.  The important thing is the proper exposure to the Sun.  For information on Sunheater Solar Heating Systems go to www.smartpool.com  I hope that this information will help warm things up. 

Sincerely.  Alan Schuster, 5/16/2004

► Keeping The Water Warm?

I heard that there is a product that you can add to the water that will help keep the temperature from dropping at night.  It that true.

Brenda, R., Michigan, 6/25/2003

► A Heater In A Shed?

Please answer this question.  Can you put the pool heater in a shed?  Give the reasons why it isn't recommended and if it can be done what are the things we need to do to insure proper safety and good performance.  Respond soon for the project has started and we need to know.

Sincerely.  Alan Schuster, 4/3/2003

► Solar Blanket Considerations?

I have two questions I hope you can help me with. My first question is, can you leave a solar blanket on a pool for a couple of days when you are not going to be swimming?  I have been told that this will cause algae to grow.  My second question is pertaining to turning my heat pump off at night. In the day my water temperature is 81 degrees in the evening I turn my pump to low speed which means my heater turns off. The morning temperature of my water is 77 degrees. Is it more economical to keep the temperature at 81 or to reheat the pool 4 degrees?  Regards.

John, Toronto, Canada, 5/22/2004

There's no reason that you can't leave the solar blanket in place for periods of time.  Just make sure that there are proper levels of sanitizer or there is a greater possibility of algae growth due to the warmer water.  I once left it on for a week and returned to 93°F and no signs of algae.  The warmer the water, the greater the difference between the water and ambient overnight air temperature.  In short, the warmer pool has more heat to lose.  It would be more efficient to leave the heat pump off, with or without a solar cover.  Enjoy the season.

Sincerely.  Alan Schuster, 5/22/2004

► A Heater For A Day?

I live in Ft. Lauderdale, Florida and it's been a little chilly lately and I'm having a pool party for my son. Is there a place that will heat your pool for a day?  Thanks.

Gina, 2/23/2007

I guess everything is a business - especially in Florida!  Glad to heat that you were persistent.  Have fun.

Regards.  Alan 2/23/2007

► Of Mice & Heaters?

We live in Connecticut and have a propane heater; obviously not used in the winter!  This year I have twice cleaned mice nests out of the heater.  I read that the heater is designed so mice do not go into it, but that is clearly not working.  Do you know of any product or method of keeping them out?  The nest was in an obvious place, but I wonder if they made it in the heat exchanger or something that would be a real problem.  People used to use moth balls to keep mice out of enclosed spaces, but I do not know if the chemical in them would be corrosive to the heater.  I could put a product like a mice killer in there, but for all I know that might just attract them.  Any thoughts or experience with this problem?  Thanks!

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