It just keeps coming back over and over :-(

[ktbunger]

I keep pool at 8 ppm and it drops to 5 each day. No OCL. Something in pool gathers at seams and wrinkles and when I sweep I discover I’ve got a dull covering of something that sweeps into a greenish cloud. Slammed at 16 for several days brushing 2 times a day. 1.5 chlorine loss first night and no chlorine loss at all second night. Water is crystal clear except when I brush it has the green cloud still. In several hours I see the stuff gathering in seams again -- although I haven’t turned off the pump in 4 days. Behaves nothing like mustard algae (climbing walls or primarily in the shade).

FC -- 16
When not slamming: FC – ranges from 8-5ppm
CC -- .5 (clears with one drop)
PH 7.8
TA 175
CYA 35
Using k-2006 test kit

First time this happened I decided it must be pollen and let it go after I passed all 3 tests and then I got a RAGING algae bloom. Slammed again at mustard algae levels and took about a week to get it back to passing all 3 tests again. Took all necessary precautions to prevent its return but now it is two weeks later and I’ve got stuff gathering on the bottom again.

This is the third time this summer I’ve been through this cycle and it has just started again. I know I can slam at mustard algae levels and get rid of whatever this is BUT I need to figure out how to keep it gone. Three kids (one of them special needs) don’t get why they can’t swim and neither does mommy.

Anybody got any ideas?
ale:

 

[woodyp]

Once you get that pool RE-SLAMmed.....you're gonna need to keep your normal FC minimum per the cya/chlorine chart in pool school at a higher than suggested level looks like. I'd also consider raising your CYA level to 50 and keep FC above that minimum amount by another point or so.

 

[duraleigh]

!. Do as woodyp suggests

2. Additionally, brush that stuff up as soon as it appears. Brushing is an integral part of the SLAM. It allows your filter to collect the debris. Are you backwashing? Do you see a psi increase of 25% and then backwash.

Thousands of pool owners follow this regimen and it works. Something in your procedure is not being done correctly but I cannot tell what that is from your post. Woodyp's advice may help....let's see.

Always remember, algae ONLY grows in a pool that has inadequate chlorine.

I don't think you told us how often you are adding chlorine and what chlorine you are using??

 

[ktbunger]

I am using 10% liquid chlorine and "pool math" to figure out how much every evening after sun is off pool. I never let it dip below the target FC and I always check the dates for fresh chlorine. Just got my gauge fixed last week but usually backwash about every 2-3 days when slamming. Weekly(ish) otherwise. I also put a scoop of DE back in the sand filter every time after I backwash. Its running at 13 PSI so I'll watch it and backwash when it gets up to 16 or so. Will get some stabilizer and get my CYA up if there is any chance that will help :0) Thx!!!

 

[JasonLion]

Several aspects of your description sound like mustard algae, and several do not. So I am not sure what to think.

If it is mustard algae, look for places algae might hide from the chlorine, like underwater light niches, and make sure they have been opened and brushed out while you were at mustard algae shock level.

If it isn't mustard algae, it could well be pollen. But then that doesn't explain how you get an algae bloom while FC levels are appropriate. Possible causes for that include bad circulation and FC levels that fluctuate more than you think they do.

None of those seem like the obvious answer. I'm just running down the possibilities in case it sparks something you haven't thought of.

 

[zea3]

Try pulling out your pool ladder and clean it well. They tend to have little niches in the back that can hide algae and circulation is usually not as good in that area.

 

[Casey]

Are you using a solar cover and keeping it on for extended amount of time? Do you have big bulky steps? Have you removed the steps? I would brush every square inch of the pool daily while at SLAM levels and as woody stated, run a higher FC level and increase the CYA. Please keep us posted on how the pool is.