Can't maintain pH?

[BabsNMK]

So a few weeks into our open pool and I'm having trouble keeping pH higher than 7.0. We opened ourselves and did a SLAM, everything is clear. But even if I add Soda Ash, the higher pH lasts for a day and then comes back down. Currently, it looks like this: CYA 35, FC 5-6 during the day (next morning it drops to 1-2...does that mean I need to keep higher during the day?), pH 7.0, TA 90. The TA started at 60 but with the Soda Ash we are now much higher.

I should also note we are converting to SWCG today or tomorrow. So I know I'll need to raise my CYA (despite working a year to lower it ), but I'm not sure how the rest of the numbers will change when that happens.

 

[thetekgeek]

How are you adding clorine now? Liquid bleach? Pucks?

 

[BabsNMK]

How are you adding clorine now? Liquid bleach? Pucks?

Liquid chlorine. No pucks. And just soda ash to raise the pH.

 

[mknauss]

Use Borax to raise pH

Baking Soda = big TA change, small pH change
Borax = Big pH change, small TA change
Washing Soda = big pH change, big TA change. Probably more TA change than you want.

 

[BabsNMK]

Ok that’s what I had planned to do. I started with soda ash because our TA was low as well. I’ll try the Borax and see if it’ll hold. How frequently should the pH need to be adjusted?

 

[ajw22]

4 ppm of FC loss per day is excessive for your area. Combine that with unable to maintain pH and you may have bacteria in the water eating chlorine and creating acid.

Add LC to raise your FC to 10 ppm and then test after 15 minutes. See if your water holds the FC at 10 ppm for 15 minutes. If it does then never mind and carry on.