War against algae or dirt?

[mbishop]

I am being driven crazy here. First order of buisness are my numbers:

FC 11
Cc 0
Ph 7.2
Ta 80
Ch vinyl liner so didn't check it.
CYA 30

As with a lot of other people, we have received an insane amount of rain this season. My backyard is surrounded by trees. My issue started second week of June when I noticed brown debris on floor of pool. Looked to me it was in the crevices so chalked it up to dirt. When I brushed it up, though, it clouded greenish. Was getting prepared for vacation so couldn't get too involved but I did take it up to shock level for a couple days before we left and before we pulled out of the driveway. Didn't really have anyone to babysit the pool as we're out in the country. Anyway, get back and first thing I did was walk around back to check the pool. Was expecting a green mess but the water was clear and I had this brown crud ALL over the floor. We had a good bit of rain while we were gone I was told. Brushed it up and it got a little dirty water looking but then was fine after about an hour or so. I convinced myself it was dirt the filter wasn't catching from all the rain and trees and wind BECAUSE 1. It's not slippery. I can touch it with my toe and rub it off. 2. It's NOT on the walls. Well, other than two seam lines. Can rub the wall and it's not slimy. 3. Not in a shaded area. The whole dang pool gets sun from about 8am until 7pm. It's everywhere!!! 4. I can bring it up to shock and hold it for dayyyssss and it's still there! 5. I did an overnight test and....yep...I passed it.

Now... since I thought it was this really fine dirt, I went and got myself a nice big ole box of DE. I can add a cup of that and within a few hours, it's calling to be backwashed where BEFORE the DE, my pressure didn't rise. Just yesterday, I had it sparkly and pretty. I vacuumed and was very happy with myself. Went out this morning and was still looking good. 20 *:$#÷× minutes after turning pump on, the brown stuff is back!!!! That happens often btw. I held a white skimmer sock over the returns to see if crud was coming out.....nothing. I was worried my filter was failing because it's like I see NO change in pressure unless I add DE.

I'm being driven crazy here. I've decided to try the shock process again. But, I don't know if I'm trying to kill something or bleach out dirt! Ugh!!! So...whated to see what you guys thought. Help me not go crazy please, lol.

 

[duraleigh]

Are you "rinsing" after the backwash?

If so, I think you might have a low level algae bloom (even if you can't see it) that your chlorine is killing but then it falls to the pool floor.

That usually happens when you aren't consistently maintaining your chlorine levels. Have you let them slip from time to time?

How are you chlorinating?

PS - it seems similar issues are almost never dirt, but dead algae.

 

[mbishop]

Yes, I do rinse after I backwash. Using plain ole bleach to chlorinate. The one and only time my FC dropped below recommended was last week when my daughter had a huge pool party. Tested at 1 and brought it up to 12 because it looked a bit hazy after having so many teens in there. This issue has been ongoing since mid June though. Water is currently sparkly but that dreaded brown stuff is on the floor and I can see every little speck of it. What I do NOT understand...no matter what on earth it is.... is why I can brush it up, DE in my sand filter will catch it, I'll backwash AND rinse, and the pool will look fabulous the rest of the day. Turn pump off, wake up next morning and it's still clean UNTIL I flick the pump back on. Within 20 minutes, you can see it reappear. Where is it hiding until then? Like I said, I put a sock over the return...nothing. brushed stuff up and had someone hold sock over return while I brushed...nothing. I quit shocking it twice so far because I wasn't getting anywhere. Started again this morning because I don't know what else to do. I brush that thing at least 5 times a day, if not more.

Question. When and IF I DO finally get this cleaned up, would my pool be a good candidate for the borates? I've read adding borates can help keep algae at bay and I like the sound of that!

Another question. If that was dead algae, would it not turn white? It still brushes up greenish clouds which is the one and only thing that leads me to think it's algae. Ugh.

 

[duraleigh]

What I do NOT understand...no matter what on earth it is.... is why I can brush it up, DE in my sand filter will catch it, I'll backwash AND rinse, and the pool will look fabulous the rest of the day. Turn pump off, wake up next morning and it's still clean UNTIL I flick the pump back on. Within 20 minutes, you can see it reappear.

A plausible explanation is that the flow of water acrros the pool floor with the pump on is allowing the debris to "bunch up" and gather in the tiniest low spots....making it visible when it was not when it all spread out. That's kind of a guess, but tiny, tiny debris collects on my pool floor in that manner and it's always dead algae.

Keep your FC around 10 ppm or so today and do an OCLT tonight....it might reveal the source as algae.

 

[mbishop]

Duh! Omg that makes so much sense I feel stupid right now, lol. Thanks.

 

[computerman]

I have been dealing with what you described all year. I can run the vacuum before the pump shuts off at night and the next morning the bottom is clear. Within minutes of the pump turning on, it starts to accumilate again. I have attached a picture of what mine looks like, does yours resemble this?

 

[mbishop]

Hard to tell by picture. My SIL has brown crud too but doesn't look the same as mine. Mine's dirt, mud, rust color but when I brush, it poofs into green. Going to just hit even harder this shock, keep DE in it, and see what happens. 3rd time's a charm! (I hope!!!!!)

 

[Beens]

I am seeing the same thing in my pool. It is perfectly clear. Passes the OCLT and I've been keeping the FC level a little high just in case.

It seems that water movement is what gathers it up in every little low spot on the bottom of the pool. Yesterday I was in the pool going in circles. (Why must I walk in circles every time I'm in there? lol whirlpool habit)

Anyway, I noticed after a few minutes of my whirlpool creating that there was the stupid brownish stuff gathering up against every little spot that would be a small ridge blocking water movement.

It wasn't showing up at all when I first got in but the current I created gathered it up against all the little high spots in the floor. It seems like it must be some ultra fine stuff that the filter just won't catch but it sure is getting on my nerves!

I hate to siphon vacuum because I lose so much water that way but it seems like it might be the only way.

I've tried adding DE to my sand filter in the past and the tiniest amount raises the pressure by 1psi but seems like there's no way that it could make any difference in that small of an amount so I've given up on that.

I would love to be rid of this stuff!

 

[duraleigh]

tiny, tiny debris collects on my pool floor in that manner and it's always dead algae.

Y'all might still be killing some organics....keep your FC up.

 

[Smykowski]

Is your solar cover clean? Any dirty pool toys/tools that go into the water?

 

[mbishop]

I've been keepin FC up and DE in the filter. Today was the first day I hadn't cursed the pool. Only a few tiny clumps! Still no CC, have passed overnite tests, water has been sparkly whole time. Whatever it is, it's leaving and that's all I care about.