Dead Algae on the bottom every day

iamnos

Member
Jul 23, 2018
22
Kelowna, British Columbia
Pool is ~3 months old, had a bit of a bloom a few weeks in, but did a SLAM and came out great on the other side. Over the last couple of weeks I'd say, we've been getting dead algae on the bottom every day. FC loss in a ~24 hour period is generally between 1.0 and 2.0. One day it was almost 3, but that was after being uncovered longer that day, and more swim time that is normal, so not totally unexpected. The lowest FC got was 3.5.

FC 6.5 (I aim for 6.5 - 7.0)
CC 0 (sometimes a very slight pink tinge, but hardly noticeable)
pH 7.4
CYA 40
TA 110
CH 130

The water is always sparkling and clear, but every day, in a few areas of low circulation, there's always this green/brown powder on the bottom. I've started vacuuming daily and brushing the walls about every other day. I did a backwash and rinse yesterday, even though we were only up about 1 PSI from normal (about 16).

Should I run another SLAM?
 

borjis

LifeTime Supporter
Aug 19, 2014
2,904
Pacific NW
I did a slam once and I only saw the dead algae clumps on the floor near the very end of it.

I would do an overnight chlorine loss test for 3 days in a row first. Then go from there.
 

Oly

Gold Supporter
Jun 28, 2017
1,095
Fresno, CA
Not sure what "a bit of a bloom" means exactly but realize you have areas in your pool where algae can hole up and be impossible to see. Light niche (area behind the light) and auto fill piping are two areas that can harbor algae.
 

frogabog

Gold Supporter
LifeTime Supporter
Jul 16, 2010
2,471
Portland, Oregon
I had some algae, very slightly cloudy water in the deep end. I realize there are areas that are more likely where algae can "hide", but shouldn't the FC and pump running take care of those areas?
Are you brushing multiple times a day? Normally yes, the pump and FC should handle even the low flow areas. But when you're dealing with an algae bloom any pool needs brushing and disturbing of the algae areas so that the FC can actually get to doing it's main job on the algae, where under normal circumstances FC doesn't need to attack so hard without algae.
 

iamnos

Member
Jul 23, 2018
22
Kelowna, British Columbia
Are you brushing multiple times a day? Normally yes, the pump and FC should handle even the low flow areas. But when you're dealing with an algae bloom any pool needs brushing and disturbing of the algae areas so that the FC can actually get to doing it's main job on the algae, where under normal circumstances FC doesn't need to attack so hard without algae.
I haven't been doing this multiple times a day. I'll start tomorrow (just closed everything up for the night). 24 hour chlorine loss was 2.0ppm being open most of the day and more than average swim time, so it's not using much.