Yesterday it lost 3 ppm FC (20 ppm to 17 ppm) between 10 am, when I started SLAMming, and 2 pm, when I checked it. Added 3 cups 6.5% chlorine, brushed. Brought it up to SLAM level FC 20 (CYA 50).
Checked again about 8 pm, FC was down to 14.5. Added 5 1/2 cups 6.5% chlorine, brushed.
Today (Tuesday) I'll move the steps and lay them over so I can scrub the bottoms of the feet, and scrub the floor really well where the algae is. I think the steps are the culprit -- the algae is in an area with low circulation and under the steps and right next to them. Time to break out the snorkel and mask, I guess.
Passed OCLT, FC 20 at 7 am. Brought FC up to 29.4 with 2 qts 1 c 6% chlorine. Now I just have to maintain that for 24 hours. Went around to the affected side of the pool, there was nothing to brush! Yay!
Still gonna tackle the stairs -- the feet are in contact with the floor and probably didn't get the full benefit of the high FC.
Took care of the steps, brushed all around where they go. Checked FC, 25 ppm. Added 4.5 cups chlorine to bring it up to 29.5. In the rain. Much less yellow staining in the areas that were yellow. Dead algae got vacuumed up. The vacuum is currently soaking in the pool, along with the skim net and the brush.
Hubby checked FC about 2 pm, it was 26. He added 4 cups chlorine and brushed around for me. Checking it for the last time at 830 or so, will bring back up to 29.5 and brush again. It's not hard, just like a SLAM really, but SO MUCH CHLORINE!!! I don't see how anything can survive it!
I scrubbed the steps from outside the pool because (a) it was raining and (b) I didn't know what essentially 30 ppm of FC would do to my skin and bathing suit. I had visions of coming out with my skin melting and the suit rotting off me as I stumbled toward the house... I think I got them as well as if I'd scrubbed from inside the pool.
Checked water, FC 22. Added 7.5 c chlorine. Brushed as much as I could see in the sun light, changed skimmer sock. Full of gunky stuff: leaves, algae, bugs. Haven't had much dead algae in the pool, really.
Tomorrow we let it start drifting down to normal. Instead of 6 ppm, I think I'll use 8 (my upper range) for my target FC from now on. Maybe that will take care of any algae lurking around. I checked all over the steps, which is the only where algae could lurk. No light niches, no ladders. Checked the weir door foam, clean as a whistle.
NO MORE ALGAE!!, she screamed into the stormy skies.
Well, finished the mustard algae SLAM successfully. No more yellow guck on the floor and steps, just dead algae on the floor which vacs up easily. FC Friday was 12.5, didn't check yesterday (big thunder and lightning storm I wasn't going out in!) but should have been around 10 (I'm losing 2 ppm a day) so today it should be right around 8, my new standard level.
I had to resort to the mustard slam recently as a SLAM a while back didn’t hold even though I passed the tests. Never saw any algae though. Just chlorine consumption and a hint of cloudy water. Once whatever it was capitulated, it took a good while for my Fc to drift back down from mustard slam levels... So far its holding and I’m now running my SWG at 5-10% for 12 hrs to keep the Fc around 7 with a 40 CYA in my screen enclosed pools with some sun sails. It’s been record blazing hot lately in central FL.
My one and only encounter with mustard algae was like this. Pool was turning a hint of green even with a healthy FC level so I took it to shock level...for two weeks...and it stayed green. Never had that happen before. So I took it to mustard level (I think it was like 24ppm or something for me) and finally the green went away. I then assumed it must be mustard algae so I brushed and backwashed and brushed and backwashed. Once the water cleared up I found lots of mustard-yellow particles collecting on the bottom. Vacuumed them up and that was it. Fortunately haven't had it happen again.