All that trichlor is what's driving your CYA so high. So...now you have a choice...do you want to run a high CYA/high chlorine pool? (See the "best guess chart" linked in my sig for more information on that). The upside is that you probably will only have to dose your pool once or twice a week, but the downside is that it's going to take a LOT of chlorine to kill off the algae bloom that you already have. Plus, everytime you let the chlorine level fall below 8-10 ppm, you're risking another bloom.

The alternative is to drain part of your water and replace it, which will drop both your CYA AND your calcium levels, if your fill water is only 170 ppm. Either way works, it's really up to you. But...you're going to have to stop using the trichlor because it's driving your CYA sky high. I'm fine with a high CYA pool--I run mine higher than most folks on purpose because I lose a LOT less chlorine that way, but when you get up over the 300 ppm range, that's higher than even I'm comfortable with. I think Pooldoc has a way to lower the CH in the pool without draining, but I'll let him answer to that to see if it's a feasible solution for your pool.


It's your decision, but we'll help walk you through whatever you decide to do.

Janet