TA 30ppm too low for pebble pool?

[miatawnt2b]

I have a 21k gal pebble pool that is now on it's 2nd full year. SWG for chlorine. From the beginning I have been keeping my TA in the 110ppm range. I typically have to add 1/2 gallon 30% muratic acid per week to keep the PH in the 7.4-7.8 range.

I went on vacation for 2 weeks, and since no one was watching the pool, I took the PH down to 6.8 before I left. When I got back, the ph was at 7.4 and the TA was now 30ppm. I haven't added anything to the pool for a week, we have used it quite a bit and still the PH is 7.4 and the TA 30ppm.

So... I think it's interesting that my PH has suddenly stabilized with this level of TA. I wouldn't have expected that. Question is, am I causing harm to my pebble or causing other issues I am not aware of with TA this low?

Thanks!
-J

 

[domct203]

How are you testing?

If this were my pool I would raise TA to 50ppm using baking soda. If your TA should continue to drop, you risk your pH crashing (<4) which is terrible for your pool.

 

[CavVet]

You want to use PoolMath to calculate your CSI. I'm not familiar with pebble, however, if your CSI is too aggressive with a low TA and pH, you may cause etching.
My fill water has a TA of 120, so i'm constantly battling high TA....if you're fill water is the same, it may creep back up on its own...but as Dom pointed out, baking soda will do the trick. Use PoolMath for that as well.
Good luck!!