First let me say thanks for this great forum. My wife and I are renting a house that has an inground vinyl pool which hasn't been open for a season or two, so we had our work cut out turning it from green (or black) to blue. Today is the first day that I'm seeing a nice blue/green in the shallow end, so we're definitely getting there after just about a week's work.
I've been keeping the pool in shock on a daily basis with 6% bleach and cleaning every day or two, backwashing a few times a day, and now I think I need to address the chemistry a bit more closely. Stats from this afternoon:
Stabilizer<20 (probably zero or close to it)
Following those meaurements, I added two 182 Oz containers of 6% bleach (just shy of 3 gallons) which should raise FC to ~ 12.5 per the Pool Calculator. I'll test FC again in a few hours and add some more if it has dropped below about 10.
The chlorine bleach seems to be doing a great job of removing the green algae from solution and depositing dead gray algae on the bottom and in the filter sand. So little by little we're getting somewhere.
I'm going to pick up some borax, baking soda, and Cyanuric Acid (CYA) to address the pH, Alkalinity and Stabilizer. Is it important to do these in any particular order? I know my CYA levels being zero is allowing chlorine to be burned off more easily by the sun, but surprisingly it hasn't been that extreme... perhaps because I'm staying on top of it.
I was thinking I would...
- add about 3.5 lbs of Borax to bring pH up to about 7.5
- wait on Alkalinity to see what kind of increase the Borax causes as I'm close to an acceptable Alk level now
- add 7.5 lbs stabilizer (split in three socks over the three returns) to bring CYA levels to ~ 30
So my questions are... first, does the above make sense? I hope to use the BBB method and hope to order a Liquidator with the 3/8" upgrade pretty soon, but in the mean time I can do it manually and supplement occasional evil 3" discs of chlorine and CYA with some caution. Is 30ppm a good target for stabilizer in this case? I figure low is better than high, at least in the sense that high is difficult to correct. Am I on target with the pH and Alkalinity or should I address Alk first?
Oh... the pool is partially shaded so it gets direct sun from about 11AM to 3PM give or take. I think that's also playing a role in my lack of stabilizer not being hugely problematic.
I should have taken photos each day, but the transformation really has been pretty dramatic. So thanks again for the wealth of information!