CYA Rose Sharply Overnight After Start of Slam. Continue?

[AzKraken]

Honestly looks like a metal stain. Copper would be one. Any use of copper based algaecides or trichlor pucks with copper in them?

I bought the house 3 months ago, so I dont have a full picture. I used the trichlor tabs that the previous owner used before. Do not believe that there is any copper in it. Have not used any algaecide.

Have stopped since and did a simultenous water exchange of 20k gallons to try to get the CYA down...and have not used anything in the pool except liquid chlorine. Only used nylon and wire brushes.

Pool had no staining before my pump broke and the algae took over.

 

[mknauss]

OK -- if what you see is black algae, you can scrape some of it off. It will be spongy and embedded in the plaster.

 

[AzKraken]

OK -- if what you see is black algae, you can scrape some of it off. It will be spongy and embedded in the plaster.

I will try to get a sample and report back later!

 

[AzKraken]

OK -- if what you see is black algae, you can scrape some of it off. It will be spongy and embedded in the plaster.

Update: Looks like at least some of it is black algae. Finally found some close to the surface and scraped it with a screwdriver. Very green once put on a paper towel. Frankly, I don't think that keeping the levels of chlorine at this CYA level is suatainable, so im going to try and do another series of partial drains to get the CYA down. The night time temps here are in the 70s now so maybe I can avoid doing simultenous water exchange this time. ugh.

 

[mknauss]

OK -- read Black Algae - Trouble Free Pool

 

[AzKraken]

Update:

I have been SLAMing (for real this time!) for over 24 hours now and at least 90% of the staining is gone and most of the bigger black dots are either gone or showing signs of degredation. I now just have to figure out what is actually a stain (I know there were some on rough parts of the pool before) and what is black algae I need to scrape.

Thank you all so much. Turns out actually following advice works much better than thinking you are. I need to do a better job at researching the usage of the tools provided in the future.

 

[AzKraken]

Final Update:

Passed a OCLT test after 3 days of 35FC SLAM. Water is perfectly clear. CYA is still very high and I have a bit of staining, but overall im extremely happy. Plan moving forward is to let the chlorine levels drop, perform a series of partial drains and refills over the next two weeks until CYA is around 60, then begin the process of balancing and maintaining for the winter.

THANK YOU SO MUCH for all the help. Thank goodness I ended up here before I ended up at a pool store or with a shady maintenence company. I will make sure to provide a donation for the site!

Ive attached a final picture to show improvement!

 

[HermanTX]

Final Update:

Passed a OCLT test after 3 days of 35FC SLAM. Water is perfectly clear. CYA is still very high and I have a bit of staining, but overall im extremely happy. Plan moving forward is to let the chlorine levels drop, perform a series of partial drains and refills over the next two weeks until CYA is around 60, then begin the process of balancing and maintaining for the winter.

THANK YOU SO MUCH for all the help. Thank goodness I ended up here before I ended up at a pool store or with a shady maintenence company. I will make sure to provide a donation for the site!

Ive attached a final picture to show improvement!

great work. You have earned your SLAM badge. What a difference in clarity.
When you do your drain and refill, that will affect your water chemistry balance so just keep on top of that so you do not get in a low chlorine situation.