I've been adding Muriatic Acid at the rate of about half a gallon a week to keep the pH down. As you can see above it is a constant battle for me, maybe because the CH has crept up over time in this new pool build filled at the end of 2022. I did post about doing a partial drain a while back but the consensus was inconclusive. I should add that currently I have the Chlorinator set to 25% for pool and 0% for spa but my FC remains elevated somewhat. Not sure why I was getting a read on CC with the water cold an chlorine high but suspect the reagent might need to be replaced. If I win the pool photo contest, I'll use the winnings for some new reagents!
If you are lowering the pH below ~7.6 that makes it rise faster as well. Try aiming for 7.8-ish with the acid and see if it slows down.
Yup. At 7.8 my CSI goes to positive which I am trying to avoid. I think a partial drain is in order. Fortunately I have baking soda and CyA on hand for the refill from my water softener so I have 0 CH when I do it. What's a good CH target? 400ppm?
That'll be a pretty big drain!! Pool math says to drain 71% of my pool volume! I better get the submersible pump from work for this..
The 1.6 HP submersibles are $83 on amazon and push near 5k GPH with a 1.5 inch hose. So even with some head loss you'd be empty in 3 hours.
The one at work is FREE! Of course I'll probably have to douse it with Chlorine!The 1.6 HP submersibles are $83 on amazon and push near 5k GPH with a 1.5 inch hose. So even with some head loss you'd be empty in 3 hours.
If they see you borrowing it, it may cost you many many thousands of dollars a year. Just sayin.
It could but I'm the engineering manager and I'll just go ask the operations manager to borrow it for a spell! I work for a local water/sewer district. It's used to pump out water from pipe breaks and we have several. If it comes down to needing the last one, I'm on 24 hour emergency call anyhow except when on vacation and it's a 10 minute drive for me to bring it back. In other words, I'm not "borrowing" it as in "borrowing" it.. I'm just borrowing it!If they see you borrowing it, it may cost you many many thousands of dollars a year. Just sayin.
I finally checked. The TA of my Fill water is 160ppm. CH is 175ppm out of the hose and 0ppm out of the softener.
Okay. So keep the CSI in the range I am trying to achieve or should I go to +0.3 ~ -0.3 range and accept the scaling so as to not erode the plaster? I'm wondering if my obsession with being slightly aggressive with CSI is to blame for the relatively high CH level in my pool. I should note that my water softener was broken for a spell so un-softened water was going through the auto-fill for several months but we've also had some pretty good rain in SoCal which should have countered this issue. I did notice my CyA dropped from 80 to 50 so you'd expect the CH to drop as well with water going out the overflow drain.
You are asking this like you can lock in your CSI to a value.
True. I shoot for pH of 7.5 to 7.8 by adding MA several times a week. It generally drifts to 8.x relatively quickly.
Understood but this puts CSI slightly positive due to high CH. Guess I'll have to live with it until next year as it's getting too warm to drain now.