I've been paying the monthly fee to let someone else worry about the chemicals. But this year, something happened and I now have algae on the walls. Not much on the bottom. With diligent care, I had it to a minimum, but the filter clogged and after a couple of days of no vacuum movement, the algae has gotten worse. I had it to the point where the water was clear and brushing with an algae brush produced almost no cloudiness. Today I backwashed and recharged the DE filter, measured water chemistry with my new K-2006 kit and then brushed the sides and the water is very cloudy :-/
I am still reading but would like some help. If I can make it through this, I will probably stop the pool service and start taking care of everything myself. But I have more to learn.
Pool: 20-22k gallons, IG, concrete/gunite
Pump: 1/2 hp
Filter: DE 36 sq ft (5 gallons/sec?)
FC: 2.5 ppm
CC: 0.5 ppm
pH: 8.0 (yes, it was very red)
TA: 375 ppm
CH: 400 ppm
CYA: 1.6 (but that was before I swept the sides)
I'm not sure how to use the pool calculator. But it appears that my pool needs acid, which will bring down the alkalinity as well. And I'll need to bring the pH down to deal with the algae.
Given the FC and CC levels, I'm surprised that algae is a problem. The pool people use chlorine gas.