Ph Down and TA went high

May 14, 2008
South Central PA
13.5k gallons
PH somewhere around 6.2
TA 160
FC 5
CYA 20

I been shocking the pool put about 10-12lbs of cal-hypo so far because of the Algae which looks like its gone. FC is steady
added some sodium carbonate 32oz (volume) to bring up PH and it looks like all it did was raise my TA
I was going to try to aerate the pool this evening with a fountain and using my air compressor any idea how long it could take?
any suggestion?
With the ph that low will it hurt my liner PH has be there about 10 hrs now and aleast another 6 before I can get to
try to fix the problem.
I run the 3" pucks in my chlorinator so I don't want to add to much more CYA other than what comes from the pucks

Thanks in advance


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May 7, 2007
Silver Spring, MD
How did you measure the PH? 6.2 is below the lower limit for the standard PH tests. Also, it is quite uncommon for PH to be anywhere near that low when TA is high. I suspect that either the PH is higher or the TA is lower, either one of which will affect what you need to do to resolve the situation. How did the PH get that low? That might tell us more about what is happening. Trichlor tablets normally reduce TA to near zero before bringing PH down that far.

PH around 6.2 will damage the liner and also the heater, if you have one and it has a copper heat exchange coil (fairly common).

Aeration will raise the PH fairly quickly when the PH is that low and the TA is that high, but it still takes quite a bit of aeration and some time to work (hours to days depending on how much aeration). If your PH is really that low you should raise it at least part of the way with borax, which can happen much more quickly.

Baking soda, sodium carbonate, will raise TA quite a bit and PH only a little. Borax raises PH quite a bit and TA only a little. Soda ash/PH Increaser raises both PH and TA. Aeration raises PH and leaves TA alone, but only works when PH is relatively low and TA is relatively high (which your test results say is the case).
May 14, 2008
South Central PA
I got the numbers from the pool store. They were trying to sell me everything under the sun. I just bought some filter basket socks
I will try the borax. as I want to get the ph up quickly so I don't damage the liner