Let TA get extremely high - trying to get under control - now scaling

[CombatYoga]

I got a little too lazy with testing my water.
Finally replaced my TFTest Kit and did a full test a couple of weeks ago.

My TA was 290! pH looked like 8.2...hard to tell if it goes higher than that.

I dumped a good bit of muriatic acid in to try to lower the TA/pH and then aerated.
TA is down to 190, but my pool has developed a chalky discoloration around the waterline tile.


1) Am I following the correct process to get my TA under control?
- add enough muriatic acid to bring the pH down to around 6.5 and then aerate

2) What is the best product to use to remove the chalky waterline stain/scale?

I searched the forum and didn't find quite what I was looking for, but if there is a post/thread where this issue is discussed (and hopefully resolved) I'm happy to start there.

Thank you!

 

[mknauss]

You should not lower your pH below 7.2. Low pH is pretty hard on your equipment and especially a heater core. They can dissolve really fast with low pH.

The process you are using is good. Just lower your pH to 7.2 and aerate to get pH back to 7.6. Repeat. Test TA every few times so that you can use the new TA value in PoolMath.

The chalky substance is calcium. You should monitor CSI - it is a calculated value done by PoolMath. Keep between -0.6 and 0.6. With existing calcium scale, being at 0 or just below for CSI is better.

You can use a dilute acid mixture to clean off the scale. I use 4 parts water one part muriatic acid with a stiff brush. Use eye protection.

 

[CombatYoga]

TFP crew FTW again! I did exactly as you suggested - it cleared most of it up. I may have to go at it again, but catching it early was key I think.

Thank you very much!

You should not lower your pH below 7.2. Low pH is pretty hard on your equipment and especially a heater core. They can dissolve really fast with low pH.

The process you are using is good. Just lower your pH to 7.2 and aerate to get pH back to 7.6. Repeat. Test TA every few times so that you can use the new TA value in PoolMath.

The chalky substance is calcium. You should monitor CSI - it is a calculated value done by PoolMath. Keep between -0.6 and 0.6. With existing calcium scale, being at 0 or just below for CSI is better.

You can use a dilute acid mixture to clean off the scale. I use 4 parts water one part muriatic acid with a stiff brush. Use eye protection.