Not sure we have algae

[game]

We have a 22×52 Intex pool. We have completed a Slam due to what we thought was mustard algae. Passed all 3 criteria . And then did mustard algae shock level for 24 hours. Then after that, we are getting what looks like dark brown/ black dust on 2 seams and some divots in the bottom. It comes back every time after vacuuming. Could this be dead algae? We have started another SLAM today because we did a OCLT last night and we lost 2.5 CH. However, it was a little windy here yesterday evening and there was a small amount of straw and dirt in it this morning which we vacuumed. And of course the same spots have the the stuff on them again. We just changed our sand out last month. Should we change it again? Also, starting tonight through Tuesday night, we are expecting a lot of rain. How do I continue the slam during all the rain. I know the rain will affect a OCLT reading. Should I just keep adding bleach until the rain goes away and then do the OCLT when the weather clears? My pool is clear and the test for CC was showing none. Any advice. My last reading I took were:
FC : 30( I am slamming)
CYA:30
PH: 7.5( before i started slamming)
ALK: 80
No calcium hardness

 

[Texas Splash]

I have a few notes to pass along:
- Let the FC fall to 12 which is your proper SLAM level. 30 is way too high (a waste and potential damage to liner over time)
- Rain has minimal effect on good water chemistry, so do your best to maint the FC of 12 (SLAM)
- No need to change sand unless you added floc or clarifiers that could unm-up the sand
- The back stuff might just be junk from your local area falling on the water and sinking - normal. But the loss of 2.5 ppm of FC overnight is not normal. A SLAM Process is warranted right now.
- Make sure your ladder/steps are removed and if you have a light look behind that as well. Inspect and clean thoroughly.

If you have more questions let us know. Good luck!

 

[game]

We are expecting 2 to 3 inches of rain each day. Are you sure that will not affect it. I will continue the slam. Thank you for your advice.

 

[Texas Splash]

We are expecting 2 to 3 inches of rain each day. Are you sure that will not affect it. I will continue the slam.

No worries. Do your best to maintain. What you don't want to do is let the FC fall making things worse. Heavy rains which result in water exchange can potentially result in a lower CYA and CH level, but do your best to keep the FC at 12. Heavy TX downpours over a long time might increase the pH a little, but again no big problem.

 

[duraleigh]

Could this be dead algae?

Absolutely. That's almost surely what it is. Continue the SLAM and don't forget to brush and run your pump 24/7 until the SLAM is done.

Disregard the rain. It will have a little affect but not enough to derail your SLAM if you test and add chlorine correctly.

 

[game]

We have passed all 3 criteria for the SLAM this morning. But since we are expecting a ton of rain over the next 3 days(3-4 inchea), I am going g to continue a high level for the rest of the day just to make sure it is really gone. Mustard algae level for 24 hours. I hope it is really gone.

 

[duraleigh]

• We have passed all 3 criteria for the SLAM this morning

  Does that include not seeing that debris on the floor? You would fail the clear water requirement if that debris was still on the pool floor.