Hi everyone - First off, thank you for all of the amazing info and tools offered by TFP. This is my first pool and start of 2nd season; and we were looking to wean off the pool company coming out to the house once per month. Your website has given me the info and confidence to do that, BUT now I'm in a bit of a jam
Last time the pool company was here, I noticed what looked like black algae (from reading previous posts: coin sized, slow growing & slow dying gray turning to black spots). I pointed it out to pool tech and he then added his magic "90 day killer/preventer" and the world was a happier place.
Fast forward a few days; and the product did nothing as the algae began to get blacker with the addition of new spots.
Here's what I think happened - My FC went from 5ppm (I tested it using Taylor K-2006) down to 1ppm in a matter of 2.5 days a few weeks ago just before the pool guy arrived. Despite adding some shock to pool (pre-BBB, I used a 4-in-1 shock from Clorox), I believe we caught it too late as the previous owners must have dealt with black algae before evidenced by some leftover chemicals in their pool closet.
I'm on day 5 of SLAMing, brushing 3x per day, and these stubborn spots won't budge. I was hoping that SLAMing with brushing was enough until I read about using Trichlor tabs and granular directly on the spots for BA vs green/mustard.
Here are my readings which I'm testing 2x per day for FC
FC: maintained at 20ppm every 8 hours (using 8.25% good ole bleach)
PH: 7.6 (when I started SLAMing and 7.8 now which I read is likely inaccurate).
I previously used trichlor pucks but switched to bleach recently and stocked up on Borax so I have it AFTER killing this BA. I'm all about the BBB over the pool company and magic additives.
So my long winded post comes down to this: Do I need the addition of trichlor to speed this up since it's black algae vs. green or mustard?
This AM was first time I passed the overnight chlorine loss test, water is crystal clear, EXCEPT for Black algae spots (roughly 12 small, individual spots).
We have a short pool season; and I can't use this beautiful pool due to 20ppm chlorine and need to kill/rid this BA Beast.
Thanks so much in advance and for all of your awesome stickies, tools, and advice -