I am a long time lurker and this is my first post.
Thank you very much to all who have shared their experiences and wisdom. What I have learned here has been invaluable.
I am 16 days into a bicarb startup after new tile and new plaster. I got five estimates and went with a DiamondBrite plaster with Azteca pozzolan and rheology modifier. (Those are a few words I didnít know until I studied this site.)
My pool company agreed to the bicarb startup and also to waiting six hours before filling. As I was waiting I saw the plaster turning several shades of gray and thought Iíd made a big mistake, but after the pool and spa were filled, I couldnít see that gray at all. Everything was a bright uniform white.
The original pool builder had told me I had a 17,000 gallon pool and I calculated the amount of bicarb based on that number. However, I wrote down the water meter numbers before and after the fill and found that about 12,700 gallons was more like it! So, I had added about 25% more bicarb than I should have. Sure enough, TA was at 400, not the 300 I had calculated. Oh, boy.
When I started up the pump, there were big jets of air coming from two of the four returns. The air was intermittent, but more often there than not. There werenít any air leaks before the tile and plaster was redone. This was something new. I couldnít see any air in the pump strainer. Everyone I asked was stumped. After I replaced pump seals and gaskets I still had a lot of air. Two days ago I listened carefully after I turned off the pump and I heard a little hissing as air leaked into the pump strainer. It was coming from the drain plug. I put a wrench on it and found that it was real easy to twist off the head of that hollow plastic bolt. The bolt head had been partly sheared off. There was my air leak! I couldnít see any air in the strainer while the pump ran because the air went from the drain on the bottom directly into the pump without showing up in the basket.
It was then that I realized that I had been running for two weeks with a very efficient aerator operating the whole time. I thought I had been adding more acid than I should have, but the pH just kept rising. Sure enough, my TA was down to 150!
So this is day 16 and I am ahead of schedule in terms of lowering the TA. TA started at 400 and dropped to 300 after the first three days. It dropped to 150 after the second week. CH started at 150 and stayed at 150 for the first week but raised to 200 after the second week. Should I add some more bicarb to raise the TA for another week or two?
There was almost no plaster dust. Even after vacuuming some storm-blown dirt the filter pressure has only gone from 12 to 14 over the last 16 days. The water looks great and the plaster is nice and smooth. The CSI (from Pool Math) today is -0.04. Would you add more bicarb? I have been keeping the pH around 7.4 to 7.6. Should I let it rise and stay 7.8 to 8.0?