I have been trying to get a community spa in shape and am having a bugger of a time. They were using trichlor tabs with a tab chlorinator. I want to drain it and start with fresh water, but the drain valve is broken and I can't get to my pool pump until this weekend and we need to keep it open short of having a community revolt. The CYA is way to high for an indoor spa so the drain will help that too.
Here are the current numbers after doing the following:
I added acid to bring the TA down to the 60-90 range (to keep foaming down) and it turned the water yellow. It was definitely a reaction, not the acid just moving through the water.
This drove the PH way down below 6.8. I added borax to bring up the PH. The TA dropped, but now has come back up to 130 since yesterday. I did NOT add Baking soda only Borax. I think the level of borates are holding the water at its current numbers keeping me from making big changes.
I had shocked it with bleach because of high CC originally. I am now using MPS shock since the health department is complaining about the FC levels and I am waiting for that to drop to reasonable levels. It is coming down, just slowly. The pool person had the chlorinator cranked up to full open on a spa with a POOL sized chlorinator.
I shocked with MPS again this am when I took that reading. I will be checking again shortly.
Short of draining it, how can I get the PH up to 7.5. The air jets have been running all day and don't seem to be helping the PH come up. I don't want to add borates since I am probably over the 50 ppm level now. No, I don't have the borate test strips.
I am going to test now and will post the results.