The pool looks much better but that *dirt* is still accumulating. Have you done an OCLT yet?
Greenish Dirt or Algae on bottom of pool
- Thread starter Blake1989
- Start date
Eagerly awaiting results! Be sure that if you make any chlorine addition tonight, that you wait 1/2 to 1 hour later and test again to know EXACTLY what your FC/CC reads so that you get an accurate evening reading. Poolmath "goals" can in actuality be under or over shot. Make sense?
Absolutely! To answer your question earlier Marian, it usually accumulates near the pool wall in clumps. I got in today and swam underwater. I felt it in between my fingers. Felt like a fine sand but not rough at all. Not slimy but not dry either. There wasn't a lot in today. Probably about two salt shakers worth and in different spots.
Hmmmm. If it changes locations, I am inclined to think it's just gunk. I could very well be wrong, but most persistent algae types tend to appear in the same places over time. Let's see what your OCLT tells us.
Notice how closely this video resembles what you have. Compare the color and consistency.
Mustard Algae - YouTube
Mustard Algae - YouTube
I see! Thanks for the video. I tested the water at 10:30 last night, and just now at 6:27 in the morning. My FC remained the same and my CC appeared to be .5 or less.
Good news! So, now bump it to mustard shock level for 24 hours. More here, Pool School - Mustard Algae
It is allergy season.... Is it possible that what is collecting at the bottom of the pool is pollen? You did pass the OCLT.
Could be. Just to be safe in going to bump my FC to mustard algae shock level for today.
Don't think that it's pollen. There's not a lot of algae compared to other types of algae and this type is very unreactive to chlorine. Therefore, it's not unusual to pass the OCLT with this type of algae.
Update: keeping at the shock level for mustard algae. Filter flow slowed considerably. Back washed and added more DE substitute. Water is crystal clear and no sign of any algae on the bottom.
Did you vacuum/brush up the "gunk/algae/dirt/stuff on the floor" or is it disappearing on its own?
I vacuumed/brushed it up yesterday and then ran automatic cleaner to scrub the bottom. No sign of any today.
Sounds like you might be done with the Slam. I would suggest keeping the pump on continuously for one week and maintain 15% for one week. Brush daily and vacuum as needed.
That's what I had in mind, thanks James. Hopefully it's eradicated. Mustard algae is no joke! Hopefully this thread will serve as a tutorial for all who get it!
A timeline question. Did the "gunk" disappear before or after you raised to mustard algae levels?