Why won't my pool get clean?

[matt4x4]

if you have to scrub a bit to remove teh "silt" then I highly doubt it's settled silt - please read:
http://www.poolforum.com/pf2/showthread.php?t=6954
it should explain what you should do.

[rilesworld]

I have read that post before, and was curious about that type of algae. Is there anyway to determine whether it is silt or algae (without a microscope). I would hate go through the extreme shock process if it wasn't necessary.

BTW I have a couple of other points. The bottom of the pool does feel a bit slimy (bad news), but this hasn't seemed to get any worse over the past month with me maintaining 3-6ppm Cl. It just won't go away. In other words, I don't get the impression that anything is multipling. Not sure if that information is useful, but it might help.

Riles

[mohawk]

We've had this same stuff since the pool was installed last year. I always thought it was dust and dirt. We had to dig out around the pool last year for code and now the grass is finally growing in, but I still get this dust the day after I vacuum. I thought maybe everyones' pool was like that. What can I say, I'm a newby. I still have a bottle of polyquat from last year. Do you think I should try that? I don't want to fade the liner. Right now I'm trying to get my CYA up since I had to drain this spring cuz of a hole. I always thought algae stuck on pool sides-that's what it does in my aquarium. Denise

[rilesworld]

The more I think about this the more I believe that it is indeed some form of algae. I do have a fair amount that clings to the walls and it is typically found in the low flow areas first.

I vacuumed yesterday evening and this morning brown deposits again could be found throughout the pool. Not a huge amount, but it has definately redeposited to some extent.

I am going to go ahead and shock as Matt has suggested and I will keep you posted with what I find out. As I said, I have had this issue for about a month, so if it clears with some heavy shocking then I can feel certain that it was indeed some form of algae.

Riles

[ivyleager]

Slickness on the vinyl surfaces ALWAYS means you're working on something growing in your pool. That's my first clue that I need to shock, which I do only rarely. Check your pool chemistry to make sure your levels are in range (CC, CA, TA, pH). If so, try these three things to sparkle up your water: 1) superchlorinate anyway to levels required based on your CYA, 2) run your filter 24/7 for the shocking, then knock it down to slightly over what you need to turn your water over; 3) use a skimmer sock ALL season. If you don't mind running the filter longer go ahead. I run mine from 8am - 6pm. I don't split up the time or need to run it at night. I'm not in California so that's not an issue. My pool ALWAYS sparkles. When it doesn't, then I know I have a problem.

Hope this helps.

CaryB
Anyone but Buffalo

[mohawk]

I've been thinking - if I add polyquat to the pool before vacuuming and the brown goes away, then I should assume it was algae-right? Then vacuum afterwards.

[chem geek]

To all posting with pool issues (rilesworld, mohawk): please post a complete set of numbers including FC, CC, pH, TA, CH, CYA. Otherwise we are really shooting in the dark here. The CYA level is very important to know as that will tell us how much chlorine is needed to battle this algae.

As for PolyQuat, it is generally not as effective at killing larger amounts of algae as it is for preventing algae from taking hold. This may be from this chemical polymer being easy to clump free-floating algae particles together and to block their ion channels, but that PolyQuat may be unable to penetrate below the surface layer of a biofilm of existing algae.

Richard