I just finished getting the algae out of my pool and would like to take the next step and add borates. It seems like a pretty straightforward process, but I am having a small problem with low CYA levels and want to make sure I'm not going to cause some kind of conflict.
So, the first question is, do I need to postpone the borate treatment until I get CYA under control? Obviously, some things are harder to move once you've borated, but I don't recall seeing anything about CYA, so I am guessing it doesn't matter, but it can't hurt to ask, eh?
The second question is just looking for guidance on why the CYA levels are so low.
We've had the AG pool for three years. The whole time it has been chlorinated with a Nature2 cartridge system using tablets and a second mineral cartridge. The pool has (predictably) been shocked quite a bit. I don't usually pay close attention to the shock I use. While there are some that claim not to affect stabilization levels, I'm willing to bet I've used some that had CYA, as well. And, I have an empty bottle of CYA that has been added over the course of the three years, so there SHOULD be some CYA in the pool...perhaps quite a lot.
In the latest go round with algae, I came across this site and am just starting out with the whole BBB philosophy. I ordered the TF-100 kit, went through the swamp/oasis process and seem to be in good shape. Prior to getting the test kit, I tested 0 CYA on a test strip, but it was a test strip and the pool was loaded with algae. I added enough CYA to give me probably a level of 10, just to keep chlorine from burning away completely, in case it really was 0. Once the test kit arrived, it still showed 0, so I added enough CYA to bring it up 10 more points. The test kit still shows nothing...well, I think 20 is the lowest it goes, but I should easily have 20 and it doesn't look like I'm in danger of having the black dot disappear any time soon....so, it might as well be 0.
Granted, it has only been three days since I did the most recent addition of CYA, so it may need a couple more days to register, but I'd still expect to see some from my history of chlorine tablets and shock, not to mention the inital dosing of CYA a week ago.
The pool has never had significant draining. Yeah, we empty some extra out over the course of the winter, but it is typically a couple inches. Overall, I doubt 1/3 of the water has ever come out of the pool.
Any idea where to go from here? My test values are:
FC = 10 (still a bit high after passing my final overnight FAS-DPD test last night)
CC = 0
CYA = 0
TA = 100
PH = 7.2 (a little low, but I'll throw in a box of borax without the MA as I start the borate process)
CH = 170