Black algae trouble

[Hammer49]

Hello everyone! Sorry to have my initial post to have so much trouble, but I find myself in a very bad spot. I have a 22,000 gallon pebble tec, SWG pool.

Well, when COVID-19 was hitting in March, my T-15 cell quit working. I ordered a new one but it took a week or so to be delivered. And, given that I have always used the BBB method, I immediately looked for bleach/chlorine. Unfortunately I couldn’t find any. I then went to 3” tablets but the battalion was apparently lost by then.

I’m struggling with overnight chlorine loss. The salt cell is fine, I’m assisting with a tablet floater. CYA is now 20-30, so I’m working to raise that to 30-50.

TC is 1
FC is .05
PH is 6.8
TA is 180
CYA is between O and 30/50

Should I SLAM the pool?

 

[Msch99]

Yes to slam. Anytime you perform an OCLT and fail, slam immediately. Assuming you have access to bleach now?

ph below 7 with TA of 180?

Surprised the CYA is so low when using tabs.

 

[Hammer49]

Yes to slam. Anytime you perform an OCLT and fail, slam immediately. Assuming you have access to bleach now?

ph below 7 with TA of 180?

Surprised the CYA is so low when using tabs.

I’ll confirm the chemistry. I have a test kit but was referring to the test strip results from this morning.

I’m still having trouble finding bleach, so I was going to dilute cal-hypo before adding it. I was also going to remove the salt cell (using the old one) during the SLAM to prevent calcium buildup.

The black algae is pretty much all over the pool floor at this point.

 

[Hammer49]

Yes to slam. Anytime you perform an OCLT and fail, slam immediately. Assuming you have access to bleach now?

ph below 7 with TA of 180?

Surprised the CYA is so low when using tabs.

Thanks for encouraging the re-check. Using the test kit, Total Alk is 70 and PH is 7.8.