Just getting started with TFP...

[rogodeter]

I haven't yet had time to go through all the PoolSchool materials and I have a question about my PH.

Just took readings and I have the below... PoolCalculator says ~180oz bleach to get to 9ppm (which I think is right given my CYA). We've run the pump quite a bit in the last couple of days.. would that aeration lead to the high pH? So I had been adding muriatic acid to reduce pH but I'm all out. Do Borax and Baking soda both work to raise pH (because I have both on hand).

Recommendations on the pH level given my below numbers? Thanks!

CYA ~100
FC 4ppm
pH 7.8
TA 110

 

[jblizzle]

Welcome to TFP!

How does the water look?

Really you should replace water to lower the CYA as a first step.

Yes aeration raises pH, and your higher TA speeds up how fast it rises.

Borax mainly raises pH. Baking soda mainly raises TA.

 

[rogodeter]

Thanks jblizzle!

The water looks beautiful. I can't really replace water more than what is evaporating as we are in a severe drought here in the SF East Bay. We're limited as to how much we can use. I've switched off the tablets and to liquid bleach for about about two months and already my CYA has gone from ~120 to ~100. My pH seems to continually go up and I have to always add muriatic acid. Given what you said, should I seek to lower my TA so the pH doesn't rise so quickly? And if so, how do I do that?

 

[chem geek]

The Pool School has an article on how to Lower Total Alkalinity, but this just speeds up a process that would occur anyway over time as you add acid. So this won't save on how much acid you add to get the TA lower, but it has you add more in a shorter period of time to lower the TA faster after which you shouldn't need to add as much acid.

 

[pooldv]

Welcome to TFP!

Yes, lower TA will help reduce PH rise. Here is how, Pool School - Lower Total Alkalinity Aim for around 80 to start with.

Keep your chlorine above minimum for your CYA, Chlorine CYA Chart

More on Pool School - Recommended Pool Chemicals

And maintaining your pool, Pool School - ABCs of Pool Water Chemistry

 

[jblizzle]

The CYA will not lower due to evaporation ... only the water evaporates. The main way to lower the CYA is by physically removing water and replacing it.

You need to keep the FC above 7ppm at ALL times to try to prevent anything for starting to grow in the pool.

 

[Agent99]

rogodeter, I hear you loud and clear about our horrible drought; I'm just over the hills from you. Perhaps over time you can do several smaller water changes. However, it will take longer and use more water.

One idea: could you use the pool water for landscape watering?

 

[GreatCanadian]

As stated above, you are lowering your pH each time you add muriatic acid. But you also state that you are adding water due to evaporation. Do you know the TA level of your fill water? Might be worth testing.