Anyone know pool chemistry?

We have a 22,000 gallon pool that was maintained as a salt pool by a Del product that is no longer manufactured. When it bit the dust, we tried to maintain as a normal chlorine pool for awhile but fought algae and chemistry constantly. We decided to buy a new generator and settled on a Circupool rj30 which is supposed to be good for 30,000 gallons. Since installing it 4 months ago, we have not been able to maintain a good chlorine level in our pool and have been battling algae blooms again. If we rely completely on the generator, running it 8 hours a day at 70%, our levels will read 0 ppm. We bumped it up to 12 hours at 80 % - same problems. Multiple calls to the company had them blaming chemistry. We tested it and adjusted levels. Phosphates and nitrates were in acceptable ranges for normal chemistry but the company kept insisting that those low levels were 'consuming' all the chlorine or that our pool had an abnormally high chlorine demand. We installed a valve 12 inches downstream of the salt cell. Pulling a sample directly from there yields a chlorine test of 0 ppm. I don't see how the chlorine can be consumed that quickly while the cell is operating. They claim it is because of a 'chlorine cloud' you can see in the cell, but testing just 12 inches away shows no chlorine. After only having the unit for 4 months and spending hundreds on extra chlorine, we had it and tried to ask for a refund. The unit has a 7 year limited warranty which is part of why we bought it. They are only offering an 80% refund. My question is this - does what they are saying seem logical? I don't want to go buy a new unit from someone else to still have problems but we ran a unit for 4 years without any of these issues on the same pool so I'm really confused. Any advice is appreciated!!

We know pool chemistry, but there's a bunch of stuff you need to know.

1. As far as I can tell, *all* SWCG (Salt Water Chlorine Generator) manufacturers 'rate' their units against properly chlorinated pools with no problem. In other words, if the water is perfect when you turn the SWCG on, it should keep up. This isn't completely unreasonable on their part: chlorine demand during a bad algae episode can easily be 10x what it is when the water is right, but nobody wants a feeder that feeds that fast normally.

2. Phosphates and nitrates are irrelevant, 95+% of the time. They (like TDS before them) just allow pool stores to sell more chemicals.

3. The relevant factors, for you are three: stabilizer level, salt level, and chlorine demand. But, strip based CYA (stabilizer) testing is so bad, as to be virtually meaningless. You need a K2006 test kit, plus the AquaChem salt titration strips, before you can really tell what's going on.

4. Meanwhile, you need to kill, or at least control, our algae. Since we don't know ANYTHING about your current water chemistry, the place to start is with PLAIN 8.25% household bleach. Your pool has a PF of 5.5, so 1 gallon of 8.25% bleach should add about 3.5 ppm of chlorine.

5. Go to Walmart and get 20 gallons of PLAIN bleach + a cheap OTO / phenol red (yellow / red drops) testkit. Also, buy 4 boxes of plain 20 Mule Team borax (detergent section). Then stop by Lowes or Home Depot and pick up 1 gallon of 31% muriatic acid. (Do NOT get the non-fuming 15% acid -- some are just diluted with water, which is fine. But some have soap in them, which you do NOT want in your pool!!)

6. Read the muriatic acid safe-handling page, as well as the "Best Guess" page. Then order a K2006 kit + the AquaChem salt test strips. Links for all those items in my blue signature block.

7. Once you have everything home, turn your chlorinator OFF. Also turn your pump ON, and turn the pump timer OFF (pump on 24/7). Add 1 gallon of bleach, via the skimmer -- NO other chemicals in the skimmer -- with the pump ON. Wait 1 hour, then test the pH. If it's below 7.0, add borax 1 box at a time, SLOWLY via the skimmer. Wait 2 hours and retest. If the pH is above 7.8, add muriatic acid, about 1/4 of the jug at a time, to the pool (not skimmer!). Wait 2 hours and retest. Continue till you get the pH in the range between 7.0 and 7.8.

8. Once the pH is OK, wait till evening, and then add 4 gallons of chlorine. Test chlorine in the early AM, and again in the late PM. Report test results here.

9. Add 4 gallons each evening, unless the EVENING chlorine test is DARK yellow. If it's medium yellow (3 ppm) or less, add the bleach.

10. As soon as you get the K2006 and the strips, test chlorine (FC), pH, alkalinity, calcium, and especially, stabilizer. Report results here, along with info on pool wall (vinyl, concrete, etc.) pool filter type and size, pool dimensions, and so on.

11. Plan to leave your SWCG *off* till the algae is gone -- none of the SWCG's should be on during an algae outbreak. They can't keep up, and it just shortens their life.

12. Once (a) the algae is gone and (b) you have the K2006 and the strips, we'll turn the SWCG back on, and see if it's working.

thread moved to the correct location.

Quote:

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Originally Posted by PoolDoc

We know pool chemistry, but there's a bunch of stuff you need to know.

1. As far as I can tell, *all* SWCG (Salt Water Chlorine Generator) manufacturers 'rate' their units against properly chlorinated pools with no problem. In other words, if the water is perfect when you turn the SWCG on, it should keep up. This isn't completely unreasonable on their part: chlorine demand during a bad algae episode can easily be 10x what it is when the water is right, but nobody wants a feeder that feeds that fast normally.

2. Phosphates and nitrates are irrelevant, 95+% of the time. They (like TDS before them) just allow pool stores to sell more chemicals.

3. The relevant factors, for you are three: stabilizer level, salt level, and chlorine demand. But, strip based CYA (stabilizer) testing is so bad, as to be virtually meaningless. You need a K2006 test kit, plus the AquaChem salt titration strips, before you can really tell what's going on.

4. Meanwhile, you need to kill, or at least control, our algae. Since we don't know ANYTHING about your current water chemistry, the place to start is with PLAIN 8.25% household bleach. Your pool has a PF of 5.5, so 1 gallon of 8.25% bleach should add about 3.5 ppm of chlorine.

5. Go to Walmart and get 20 gallons of PLAIN bleach + a cheap OTO / phenol red (yellow / red drops) testkit. Also, buy 4 boxes of plain 20 Mule Team borax (detergent section). Then stop by Lowes or Home Depot and pick up 1 gallon of 31% muriatic acid. (Do NOT get the non-fuming 15% acid -- some are just diluted with water, which is fine. But some have soap in them, which you do NOT want in your pool!!)

6. Read the muriatic acid safe-handling page, as well as the "Best Guess" page. Then order a K2006 kit + the AquaChem strips. Links for all those items in my blue signature block.

7. Once you have everything home, turn your chlorinator OFF. Also turn your pump ON, and turn the pump timer OFF (pump on 24/7). Add 1 gallon of bleach, via the skimmer -- NO other chemicals in the skimmer -- with the pump ON. Wait 1 hour, then test the pH. If it's below 7.0, add borax 1 box at a time, SLOWLY via the skimmer. Wait 2 hours and retest. If the pH is above 7.8, add muriatic acid, about 1/4 of the jug at a time, to the pool (not skimmer!). Wait 2 hours and retest. Continue till you get the pH in the range between 7.0 and 7.8.

8. Once the pH is OK, wait till evening, and then add 4 gallons of chlorine. Test chlorine in the early AM, and again in the late PM. Report test results here.

9. Add 4 gallons each evening, unless the EVENING chlorine test is DARK yellow. If it's medium yellow (3 ppm) or less, add the bleach.

10. As soon as you get the K2006 and the strips, test chlorine (FC), pH, alkalinity, calcium, and especially, stabilizer. Report results here, along with info on pool wall (vinyl, concrete, etc.) pool filter type and size, pool dimensions, and so on.

11. Plan to leave your SWCG *off* till the algae is gone -- none of the SWCG's should be on during an algae outbreak. They can't keep up, and it just shortens their life.

12. Once (a) the algae is gone and (b) you have the K2006 and the strips, we'll turn the SWCG back on, and see if it's working.

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Follow the above advice TO THE LETTER and you will be fine.