Hi! I have a 34K gallon white plaster inground pool. In the past 2 weeks, my pH dropped from a consistent 7.6 to 7.2, and my chlorine level from 3 to .5-1.0.
I have an off-line chlorinator, which is now open to 7, and a DE filtration system. I had an algae problem (green/brown on walls only)3 weeks ago, and shocked the pool, brushed walls, and was religious with cleaning skim baskets, filter by main filter, and polaris bag.
While the pool seems "algae free", I am still out there brushing anything that looks like regrowth. My other levels, as of this morning are: TA: 100, CH: 360 and CA: 40.
My neighbor had a similar algae and Chlorine/pH problem, and after navigating your sight, used the Borax and bleach and the algae is gone, and the chemistry is perfect. Also, I have to say in NJ this season, we have had ALOT of rain, and I thought this also contributed to my algae/chemistry problem.
I am religious with testing the water everyday with a test kit, and even will bring a water sample to the local pool supply store to check my values against theirs. Since the pool was put in 4 years ago, my pH has always been 7.6 and my chlorine at 3-4. The water for the past week is crystal clear, but I hate fighting those 2 chemistry values!
Using the pool calc, it says I should add 148 oz. by weight or 142 oz by volume of the 20 Mule Team Borax, and 282 oz. of 6% bleach (Chlorox)...so would that be 9 solo cups (16 oz) of Borax?
And what about testing now for Borax? I feel since it is supposed to rain again, that I should do the Borax FIRST to raise my pH, then do the bleach...also, what is the time frame between application of Borax and bleach, and is it better to reconstitute the Borax in a 5 gallon bucket of pool water then broadcast in front of the return, or pour in powder as is? Sorry for all the questions, but I want to do this right...Thanks so much!!