Above Ground Pool

[tcj1313]

I have an above ground pool and I need help balancing out the chemicals. I have tested it and the test shows:

Total Hardness: 200

Free Chlorine: 2/4 but goes to 0 in about 2 hours

pH: 6.8

Total Alkalinity: 240 or higher

Cyanuric Acid: 0

How can I raise the chlorine, and Cyanuric Acid and lower the Total Alkalinity? Please help I have been trying to fix this for months now.

Thanks,

[chem geek]

Since you are measuring Total Hardness and not Calcium Hardness it sounds like you are using test strips. You should first get yourself a good test kit: either the Taylor K-2006 you can get at a good online price here or the TF100 kit from tftestkits.net here with the latter kit having 36% more volume of reagents so is less expensive per test.

The reason your chlorine isn't holding is that you have no Cyanuric Acid (CYA) in the water. You can add this in one of two ways. One way is to buy Cyanuric Acid (nearly pure 100%) from a pool store. Use The Pool Calculator to calculate dosage for your pool. To have this added more quickly, put it in a sock or panty hose and hang it over a return flow. Or you can add it into a T-shirt in the skimmer IF you have alternate flow to your pump (i.e. floor drains or the skimmer has an alternate flow pipe in the pool). If you add pure CYA in this way, then you should add chlorinating liquid or 6% bleach slowly over a return flow with the pump running to add chlorine to the pool. The other way is to add Dichlor which will add both chlorine and CYA to the pool. For every 10 ppm Free Chlorine (FC) added by Dichlor, it will also increase CYA by 9 ppm. You don't want to add too much CYA to your pool -- start out with around 30 ppm and see how things go from there.

You lower the Total Alkalinity (TA) by following the procedure described in this post. Your pH is already low right now so just aerate the water to get it up to around 7.0, assuming that is the next to lowest reading on your pH test. Then keep aerating and when the pH rises, add acid to keep the pH low. This will lower the TA over time by an amount that is solely a function of the amount of acid you add (The Pool Calculator will give you an idea of how much that is, though you do not add all the acid at once -- you only add acid to keep the pH low while aerating).

See the Pool School for more info.

Richard