Ok, I am now certain this is black algae as I recently found a slight larger patch and scraped it off on my fingernail to see green. I had a failing SWG (ecomatic) before that the pool had when I bought the house. Because of this the chlorine has dropped sometimes below recommended levels. Also, at first I had no stabilizer in the pool because thats what my pool store recommended. I have since read up a lot (this site is so helpful) and learned a lot. I know not to trust what my pool store was telling me. I now have a new hayward aquarite T15 installed on my 21.300 gallon pool. The places I see the algae are on a few very small spots where the pool has some shade, on my top step where the water is shallow, and around all around the pool at the waterline (in between each and every tile). I read the pool school link. Last night, I thoroughly cleaned and metal brushed everything. I put the SWG on superchlorinate. Now I plan to follow pool school advice. Few questions:
1) My pool is 3 years old and gunite (is this plaster?), can I use a metal brush all the time including weekly maintenance or should I use a soft bristle for weekly maintenance? What brand / type brushes are recommended?
2) Is it okay to use the superchlorinate option on my T15?
3) If I could instead, just keep the black algae at bay, could I just wait until I close the pool out for the winter (what I mean is, would it die over the winter months)?
4) At what pool FC levels is it safe for me to still get in the pool? I can scrub much harder on some spots if I am actually in the pool.
Thank you!!
1. My pool is gunnite and I was told by multiple people to brush with a wire brush to break through the waxy coating the algae has and then to get to the little filaments/roots that penetrate the plaster. This is like a marine algae you might see on a rock, they stick! I bought my metal brush from the PS. I just had my plaster patched in the spring so it was painful to have to use this metal brush. No other way apparently. Right after you brush SLAM the pool so the chlorine hits the brushed algae!
2. I don't know the answer to this
3. I would kill it completely before closing the pool--that is me. Who knows what will happen all fall, winter and early spring?
4. I have heard that commercial pools keep their chlorine at 10, not sure if that is true but I have swam in my pool when it was 8 and could not tell the difference.
The thing is you don't want your free chlorine levels to go Dow at all since it gives the algae another foothold. Shock the heck out of the pool and be sure to include all your equipment in the chlorine pool including your robot as the spores will get everywhere even into bathing suits and pool toys. Wash them or soak in pool with shock level chlorine.
It is a nightmare to have black algae. In addition to shocking and keeping chlorine levels high I used trichlor when gone during the day to maintain levels. Don't stop keeping levels high even after you see the algae gone--like instead of 3 keep it at 7 or 8 all the time for maintenance. Good luck with it all!!
Sent from my iPhone using Tapatalk Pro
40,400 inground gunnite, max depth 10-ft with 1.5 hp single speed Pentair, DE filter, well water, only one skimmer working, TAYLOR TK-2006 TEST KIT COMP CHLORINE FAS-DPD, Chester County, PA--OLD pool, but a beauty.
