Acid Question

[SanMarzano]

Hello Everyone

I can seem to find the answer for this. I use the Pool Calculator to get amounts to add for LC and MA. Normally I dont fill everything out but today I noticed the amount of MA to add changes based on the TA level (if I write TA as 60 it tells me one amount, if I put in 90 it says another). Why is that?

Also. Is TA suppose to be between 60-120. And CH between 220 and 320? I hear conflicting things here

Here are todays numbers let me know if you think all is on track

FC 5
CC 0
PH 7.9 (added to lower to 7.5)
TA 90
CH 275
CYA 40

Thanks

 

[Texas Splash]

We always use the Pool School - Recommended Levels to verify what our levels should be. A couple of the items changed last season, so it's always good to check for accuracy. It's best to fill-in all the parameters on the Poolmath calculator since some items can/do influence each other - even the water temperature. In simple terms, we know that TA serves as a buffer for pH, so it's easy to see how those two can relate - to include their side-effects on your CSI if you're in an area with exceptionally hard water (calcium). All-n-all, your numbers look very good.

 

[zea3]

MA lowers TA and pH. For a manually chlorinated pool you don't want TA to drop below 70. SWGs tend to raise TA and pH over time so they can go as low as 60 for TA. As to how high TA should be that depends on your circumstances. Usually we only worry about TA when pH is unstable, CH is over 400, or TA has dropped below 60.
You want to adjust TA when pH is unstable to help prevent wide swings in pH readings. This tends to happen when TA is low. Also we recommend lowering TA to the 70-90 range if CH is over 400 to reduce the risk of calcium scale formation. Keeping pH and TA lower prevents calcium scale in high CH concentration water when replacing the water is not practical. If you TA gets too low, say below 60 that is when you will see unstable pH readings, or pH that drops below 6.8.

Poolmath is designed to account for different variables for the values that can affect other values when adjusted. Since TA is lowered by adding MA, putting in your actual test result is going to give a different recommendation than leaving whatever the last test result entered will give.

 

[SanMarzano]

Thanks Everyone