Algae growing behind pool lights

[drewgost]

Moved from here.
I have the same issue with lights, I pull them out and sure enough the green comes out. Mine are out right now and I am thinking of putting in a chlorine puck behind each one.
Any thoughts? good bad or otherwise.

 

[Rancho Cost-a-Lotta]

I have the same issue with lights, I pull them out and sure enough the green comes out. Mine are out right now and I am thinking of putting in a chlorine puck behind each one.
Any thoughts? good bad or otherwise.

Trichlor is more dense than water and pretty acidic. It etches and discolors plaster. I'd bet you'd eventually see plaster staining under the lights as the trichlor dissolves and works it's way down.

 

[drewgost]

Thanks for your input Mike, ill skip the pucks.

 

[duraleigh]

Algae in the niche is an indicator your FC needs to be elevated, Particularly if you are getting some on the walls outside the niche.

Can you post a current set of test results?

 

[drewgost]

HI Dave, I am going through a slam at this moment I notice on Monday my FC was zero so i added LC and brought it up to the levels below.
5/16 FC 8.2 CC .5
5/17 FC 0.0 cc 0.0
5/18 7PM I added 4 gallons 12.5% LC did not get a read for FC
5/19 4AM FC 26.5 and cc 1.0
5/19 3:30PM FC 15.0 and cc 0.5 did not add any more LC
5/20 3:30PM FC 8.0 and cc.5 My CYA is at 30-40 should I add 1 gallon at sunset to bring FC up to 12-16? This time I will check the FC before I go to bed and when I get up at 4AM
CYA between 30-40
TA 100
pH 7.5
CH 300

 

[drewgost]

I also opened up the filter to a nasty looking color I hope it is pollen, but could be algae.

 

[MITBeta]

Why wait until sunset? The SLAM Process works best the more consistently you can keep FC at SLAM level. Add chlorine now and test and add again at least once more tonight.

 

[IceShadow]

Take just a minute to read (or re-read) this link: SLAM Process

You want to add chlorine often to get back to your target. If you're between 30 and 40, round up to 40 and target 16 for FC. Bring back to that as often as you can to get the crud in the water killed.

 

[drewgost]

Thanks for the reply I thought it was best to put the FC in without sun beating on water but sure, I will throw in a one and a half gallon now and get reading in 30 minutes then check in the AM for loss.

 

[IceShadow]

Check and add hourly if you can. If not, 2-3 times a day minimum. You want to keep that FC up whether or not the sun is on the pool.