Green Dust

[danzgator]

I check my chemical levels pretty religiously 2-3 times per week and am always at or close to where I should be, however every few weeks my pool starts to have green dust (Algae?) settling on all horizontal surface. At first it’s very little, I can get away with brushing 1-2 times per week but it progressively gets worse until there’s thick green dust every day. I clean the filter out, it’s completely green, but clean besides that. I SLAM the pool, it clears up, I do the overnight test and when it passes I let chlorine levels drop back to normal, it’s fine for a few weeks, then it happens again. My minimum chlorine level is 3, but I’ve been keeping it at 5-6 since the last SLAM and it happened again. The only thing I can think of is that since we use lake water for irrigation, maybe some of that is spraying into the water. Thoughts on how to stop this cycle?
FC: 6
CC: 0
PH: 7.7
TA: 70
CYA: 70

 

[Jimrahbe]

D,

I would have to assume that you are never really completing your SLAM.. You really should only have to SLAM once and then just maintain the FC at our recommended level. The next time you do a SLAM go with the next higher SLAM level and go for two days after you think the water has passed the three SLAM criteria.. This will compensate if you are off on your CYA level or FC measurements.

Another possibility is that you have algae at some hard to reach area, such as under a ladder or behind a light.

Let's see what our other members have to say.

Thanks,

Jim R.

 

[danzgator]

Thanks. I will do this. Is it safe to run the robot at those high levels, or should I manually brush?

 

[Jimrahbe]

D,

While I am a great Robot fan... I would use a brush.. Not because the robot would care much about the FC, but because I think manual brushing will do a better job, from a SLAM point of view..

Thanks,

Jim R.

 

[ajw22]

Can your pool pass the Overnight Chlorine Loss Test?