Ph and alkalinity is always high

Problems relating to pH and total alkalinity.
Increase ph, increase TA. Reduce pH, reduce TA.
pH chemistry advice and techniques for the pool.
crow-toes

Ph and alkalinity is always high

Postby crow-toes » Wed 29 Apr, 2009 19:57

i have a salt pool and the ph and alkalinity is always high i have added roughly 4 gal of acid but it is still high it is 14000 gal pool with a aggrigate finish i see a lot of scaleing particals on the bottom of the pool it seems like i can not get it under control please help


chem geek
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Ph and alkalinity is always high

Postby chem geek » Wed 29 Apr, 2009 21:34

Continued addition of acid over time should be lowering the TA level in your pool. If it's not, then you are adding TA somehow, most likely from evaporation and refill of water high in TA. Do you know the Total Alkalinity (TA) and Calcium Hardness (CH) of your fill water? Do you get a lot of water evaporation where you live (see this map for annual evaporation in inches per year).

You can lessen the rate of pH rise in your pool by lowering your TA via the procedure outlined here. Your Cyanuric Acid (CYA) level should be at around 70-80 ppm and your target Free Chlorine (FC) level around 4 ppm. You could also use 50 ppm Borates in the pool. Let's first figure out why your TA isn't dropping and can go from there.

Richard
Pooltech32
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Ph and alkalinity is always high

Postby Pooltech32 » Thu 30 Apr, 2009 00:07

I add about 1 liter of muriatic acid per week to my salt pools, it is a common issue with them regardless of how old they are. the pools I look after are approx 25,000 gallons so you should expect to add about half a liter weekly, test you PH first of course
Pool repair guy
crow-toes

Ph and alkalinity is always high

Postby crow-toes » Thu 30 Apr, 2009 20:42

does any one no what is causing all the scaling pieces in the bottom of the pool same person with high ta and ph thanks in advanced
chem geek
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Ph and alkalinity is always high

Postby chem geek » Fri 01 May, 2009 02:39

The scale is calcium carbonate from having too high a combination of pH, Total Alkalinity (TA) and Calcium Hardness (CH). As Pooltech32 noted, saltwater chlorine generator (SWG) pools tend to rise in pH, but your adding acid should over time lower the TA even if the pH keep coming up later. You can reduce the rate of pH rise from the SWG and reduce the scaling by 1) having the CYA be 70-80 ppm and your FC at 4 ppm which should let you lower your SWG on-time, 2) lowering your TA level and 3) adding 50 ppm Borates to the pool. See Water Balance for SWGs and Lowering Total Alkalinity.

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