CYA gone? Green Pool...

[Anjayla0021]

Took my solar cover off to some greenish water today..sigh. Here are my numbers immediately after I did that. Mind you, FC is on the lower end, but my SWCG runs for about 4-5 hours at dusk with the filter for 8 hours.

FC: 4
CC:0
PH: 7.5
CH: 100
TA: 90
CYA: 50

The pool is a greenish color with brown colored "patches" along the bottom of the bottom. The pool temp has been about 80-85. What alarms me is my CYA. Its usually at 80. I opened the pool two weeks before memorial day and thats when I added new CYA for this year to bring my number up to 80 after my initial shock opening.

I know I need to bring that CYA up, but with the pool having chlorine in it and it seeming like functionally the SWCG is doing its job by keeping it in my ideal range of 4-6, how to I tackle this issue? Last year, I never had to add to my CYA..it always stayed at a steady 80.

ETA: How many days can you keep a solar cover on? Could I have kept it on for too many days?! The water itself is clear. My eyes could be deceiving me, but could it just need to be vacuumed? Most of the “color” is at the bottom but I can still see through the water.

 

[wayner]

Higher CYA requires more chlorine so low CYA means your pool should be OK with a lower FC level. You should have a higher level than 50 but the CYA test is, at least IMHO, wildly inaccurate. But low CYA is not your problem in the short term. You will likely need to SLAM your pool.

 

[Anjayla0021]

Higher CYA requires more chlorine so low CYA means your pool should be OK with a lower FC level. You should have a higher level than 50 but the CYA test is, at least IMHO, wildly inaccurate. But low CYA is not your problem in the short term. You will likely need to SLAM your pool.

Assuming I slam with a CYA reading of 50 then? Its not on the chart for a SWCG so I assume I go by non SWCG and turn mine off during this process? After slamming and doing the OCLT, should I bring the CYA back up to 80? Just seems odd it went down so much.

Starting the slam and vacuuming now.

 

[zea3]

Raise the CYA after the slam is complete. Keep the SWG off during the slam and use unscented, plain bleach without any additives as your chlorine source.