Buildup of stuff in electrolytic cell

[abru88CJ]

I have puzzling problem with my Intex 18' above ground pool with salt system. The electrolytic cell has been experiencing a heavy build up of calcium deposits. The Intex FAQ says it is due to high levels of calcium. Atlanta water is fairly soft. I had to clean the cell May 16 and again June 5. My pool chemistry is as follows:

pH 7.6, free Chlorine 5 ppm, total alkalinity 100 ppm, Calcium hardness = 260 ppm, Cyanuric Acid = 35, salt level = 2900. Analysis at Leslie's Pool Supply.

Intex Preferred level:
pH 7.4 - 7.6, free Chlorine 1 - 4 ppm, total alkalinity 100 - 140 ppm, Calcium hardness = 200 - 400 ppm, Cyanuric Acid = 30 - 50 pm, salt level = 3000.

Does anyone have any ideas on what is happening in the pool? I can't call Intex tech support- they are so overloaded the answering thing won't even try to connect me.

I hope this isn't too long or detailed.
Richard

[chem geek]

The fill water in Georgia (as seen in the map in this link (http://ga.water.usgs.gov/edu/characteristics.html)) is indeed fairly soft in the 0 - 60 ppm range. So did you add calcium chloride (Calcium Hardness Increaser) at some point to your pool? You don't need to do that with a vinyl pool such as the Intex you have. That is part of the problem. The other part is that your Total Alkalinity (TA) is too high since for a saltwater chlorine generator pool it would be better to be lower, say around 70 ppm, to reduce the rate of pH rise if you've been adding acid to keep the pH down (if not, then that's not as much of a concern).

There are several things you can do to reduce the buildup of calcium carbonate in the salt cell. One is to lower the TA level through a combination of acid addition and aeration at low pH (around 7.0). Another is to lower your CH by partial drain/refill. Another is to add 50 ppm Borates that will be an additional pH buffer particularly helpful at keeping the pH from rising so much in the salt cell.

[PoolDoc]

As Chem_Geek suggests the problem is probably something you added -- probably were TOLD to add. I'm coming up with 6,600 gallons (18' x 48" wall) -- if that's right, it might be easier and cheaper to drain and refill, than to try to fix the water.

Take your tap water to Leslies and have it tested -- if it is indeed low in calcium consider draining and refilling. Once full, do NOT add calcum hardness increaser and do NOT use shocks or other products containing calcium hypochlorite.

Do use bleach to start up -- 1/4 gallon of PLAIN 6% household bleach per dose.

Read the test kit page (my signature) and then get a test kit -- you won't be able to effectively manage your pool without one. Pools store testing varies from acceptable to totally random -- with bad, random results more the rule than the exception.

Once all this is done, and you have your pool up to speed with correct chlorine, salt and stabilizer levels -- you'll have to acid clean your SWCG plates before you put it back into operation.