High PH every 30 days or so

[dw9000]

I've had my pool 5+ summers so I am not a newbie. Normally I bring the PH down at the beginning of the season and it stays down for the most part of the 3-4 month pool season here in Northern Ohio. Last year, I had high PH, noticed the pool robot had a white powdery coating. I added a full gal of muratic acid. Brought it down to normal within a couple hours. 30 days later, same thing.
I didn''t do a full battery of water tests, but I am certain my chlorine is normal, my CYA is normal, Alkalinity normal, etc. I tested it earlier and sure as Darn the PH is high again, after adding muratic maybe 30 days ago. Is it normal to have to add a 1/2 to full gal of muratic acid every 30 or so days to keep the PH down?
BTW - I bought a spray bottle of CLR and it cleaned up the pool robot, the pool ladders, etc. That stuff is magnificent.

 

[mknauss]

pH rise is due to TA and aeration. What is your TA? Do you use fill water? What is the TA of that fill water?

 

[SoCalTFP]

That doesn’t sound too extreme, we have high TA fill water and a spillway we run when we’re using the pool. 1/2 gallons for a ~12k pool is pretty standard every week. Also might depend what PH you’re targeting, the lower your target or addition level the more frequently you’ll add.

Borates might help a bit too, but don’t expect miracles. Probably costs a lot more than the $5-10 a month in MA you’re adding.

Are you tracking CSI? I inherited scaling which is a PITA so I’d be far more concerned about that.

Maybe post us full test results and TA/CH levels from your fill water.

 

[dw9000]

Thanks mates! I'll measure the TA and SoCal makes a good point, adding .5-1 gal of MA a month isn't the end of the world as long as it doesn't have a negative effect.