First time poster here - HELLO. I found this forum a year ago and I really appreciate it! I have learned a lot and I don't go anywhere else for pool advice. I wish the entire internet was a helpful as this site!
I have an algae and balancing problem that has me stumped. Here are my vitals from a Taylor test kit that I bought based on your advice (thank you). I used to live on test strips (, I know).
Pool: In ground gunite/plaster; approximately 25,000 gallons
PH: 7.8 (after 3 gallons of Muriatic Acid applied in past seven days - it was 8.0 last week)
TA: 190 (again after 3 gallons MA in past week - it was 200 before that)
FC: 5.5 ppm (adding approximately 3 gallons of liquid bleach a week since mid-May)
CC: 0 ppm
CYA: >100 - I didn't want to expend the whole chemical bottle to see exactly how high
I have persistent yellowish algae growing along all sides of the pool, from the tile waterline on down about 36 inches. This started in mid-May. I have been in this house for three years. In year 1, after I dismissed the pool guy, use used 3" trichlor tablets exclusively. It kept things very clear... until year 2 in May/June, this yellowish side algae started. I found the TFP site, and determined that my trichlor regime was a problem - crowding out the FC content of my chlorination, and I took the advice to use liquid chlorine exclusively since. I also got the Taylor kit and managed my PH in a range of 7.6 to 7.8. TA was usually 160 - 180. My algae problems were soon gone - I simply added about one gallon of liquid bleach every other day during the summer. My FC remained about 7-8 as a result. Winter is not a problem (this is California).
This summer, right on queue, the yellow algae on the sides returned. I added more frequent liquid chlorine but I noticed that it didn't stay up (say 6-8 ppm) for very long - quickly falling back to about 2 ppm. Then I determined I needed to get my PH down (it has been hovering between 7.8 and 8.0). I added muriatic acid - slowly at first - but it really had no effect. Last week I decided to apply a more aggressive treatment of MA. Based on my numbers, I could target a PH of 7.0 by adding about 2 gallons. 24 hours later, I am at 7.8 (barely any movement). And my TA is virtually unchanged.
I do realize my CYA is a problem, causing me to have to target a very high FC. Last year I got things under control with FC at about 8 ppm, even with 100+ CYA. This year it is not cooperating. I can keep an FC of 8-10 for a day by adding a lot of bleach, but it I suspect my PH being so high is reducing the effectiveness and lifespan of my chlorine. We are in a severe drought in California, and I cannot replace significant amounts of pool water to lower the CYA. Last year I somehow managed to keep PH around 7.6, FC around 8, and my pool was very healthy. This year I am constantly sweeping the sides - every other day, and I just cannot keep up with the algae .
Am I getting distracted by the PH reading now - should I only bombarding with bleach until I get the algae under control? Any advice is whole-heartedly appreciated!