I need help. I found this website through a Facebook group where I posted about having mustard algae I couldn't get rid of. Or at least that's what I think it is. Everyone I've talked to says it's mustard algae. I'm a new pool owner. We bought the house in March and opened the pool in April. I've been learning/working on the pool myself for 2 months. After several bags of shock and a couple tries with yellow out I decided to try this slam method as my kids are bugging me about when the pool will be ready.
I just got the proper test kit 2 days into the SLAM. I thought I had the right one but it had DPD but not FAS. I bought a bunch of liquid chlorine as well and I took the pucks out.
Test results when I started:
FC 10 (Because I'd already shocked it multiple times with the bags of granular stuff)
TA 150
PH 7.5
CH 390
CYA 50
So today is day 4. The pool was clear yesterday, but last night after dark I saw something collecting in the bottom corner of the deep end again. Not sure if it's algae or just dirt falling into the pool and collecting in the corner. Also it's been raining off and on for the last 24 hours. This morning I passed the OCLT, and the CC has been 0.5 for a couple of days. I came back after the sun was out, to find it seems the algae continues to grow in the corners of the deep end, as well as a few spots in the corner of the ramp and the edge of the shallow end. The spots in the corner of the ramp is that yellowish-green color. The stuff in the deep end appears to be dark in color, not jet black but dark grey/charcoal in color.
Pictures enclosed. You can see it against the seams. That stuff brushes off. Overall pic of pool with pool equip/ladder being sanitized. Pic of tree canopy to show how often stuff is falling into the pool.
I had planned to increase my target FC to 30 for 24 hours as the mustard algae post says but now I'm not sure.
My current FC is 22 and my current CC is still 0.5.
Maybe it's not algae?!?
Should I stay the course or increase my target FC?
Headed out the brush & vac again. Any advice is well welcomed. Hopefully, I've provided all the pertinent information and didn't break any forum rules as this is my first post.
Grateful for this community. Thanks in advance.






-Webster
I just got the proper test kit 2 days into the SLAM. I thought I had the right one but it had DPD but not FAS. I bought a bunch of liquid chlorine as well and I took the pucks out.
Test results when I started:
FC 10 (Because I'd already shocked it multiple times with the bags of granular stuff)
TA 150
PH 7.5
CH 390
CYA 50
So today is day 4. The pool was clear yesterday, but last night after dark I saw something collecting in the bottom corner of the deep end again. Not sure if it's algae or just dirt falling into the pool and collecting in the corner. Also it's been raining off and on for the last 24 hours. This morning I passed the OCLT, and the CC has been 0.5 for a couple of days. I came back after the sun was out, to find it seems the algae continues to grow in the corners of the deep end, as well as a few spots in the corner of the ramp and the edge of the shallow end. The spots in the corner of the ramp is that yellowish-green color. The stuff in the deep end appears to be dark in color, not jet black but dark grey/charcoal in color.
Pictures enclosed. You can see it against the seams. That stuff brushes off. Overall pic of pool with pool equip/ladder being sanitized. Pic of tree canopy to show how often stuff is falling into the pool.
I had planned to increase my target FC to 30 for 24 hours as the mustard algae post says but now I'm not sure.
My current FC is 22 and my current CC is still 0.5.
Maybe it's not algae?!?
Should I stay the course or increase my target FC?
Headed out the brush & vac again. Any advice is well welcomed. Hopefully, I've provided all the pertinent information and didn't break any forum rules as this is my first post.
Grateful for this community. Thanks in advance.






-Webster