Brown spots/streaks on floor of agp


New member
Jul 17, 2019
Orland Park IL

I opened my pool about a week ago. Balanced chemicals /added Borax to up low ph. Shocked with liquid.
A few days ago I noticed a few brown spots or streaks that are lying in crevices or low spots of floor. No spots on wall. Water crystal clear. I figured maybe it was sand from the pool stair weights. I hooked up the automatic robot cleaner with filter. It removed all the spots and I thought all was good. 1 day later they returned. Vacuumed again with robot x 2. A day later they are coming back.

Is this an algae? A mineral copper/iron?

Please advise! Thank you!

PH - 7.5
TA - 110
TCL - 10
FC - 10
Hardness - 160



Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Welcome to the forum :wave:

Is this an algae?
Almost surely that is dead algae. You will need to SLAM the pool but it will be a short SLAM.

Please read the SLAM article in pool school and then ask lot's of questions. We'll all help make that stuff disappear permanently
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