I think I may have a problem with my sand filter, plz help

[cmayes71]

I had what I thought was mustard algae in my pool. There were brown streaks all over the bottom of the pool. It was easy to brush off. Kind of like a powder. My steps had a yellow powder all over them. For 24 hours I shocked at a mustard shock level. Before shocking at mustard shock I shocked at a regular shock level. Last night the chlorine held and I have kept my chlorine at 7 today. The pool looked great except for a very slight cloudiness. We turned the pump on high and within an hour there are brown streaks all over the pool. We keep our pump on 24/7 on low but will turn it on high a couple of hours daily. I've read on the forum about channeling and wonder if this could be the case.

Todays readings are: Chlorine 7, ph 7.5, cc 0, CYA 30. When I shocked at mustard shock I kept the chlorine at 19. Regular shock 13.

Yesterday I scrubbed the entire pool down with a brush. We backwash about once a week. We have a stocking on the skimmer basket. I check my levels daily and keep the chlorine at 4.

Do you have any suggestions? It was such a disappointment to go out there and see all that dirt in the pool after working so hard to clean it.

This forum is awesome. It's been a great tool. I plan on becoming a supporting member this month.

Thank you.

Cindy

 

[saltyarkansas]

Hey, Cindy!

I'm new to this forum as well and I'm sure one of the experts will be along to offer some expert advice, but I recently had the same problem. If you're absolutely sure it's just dirt, it may be that your sand filter is just not capturing all of it. Try adding some DE to your filter. There's directions in Pool School. I'd post the link here for you, but I don't know how yet. :? Make sure you follow the directions closely. I've added DE to my sand filter twice in the last 2 weeks and the dirt is much better now. The DE really causes the filter pressure to increase rapidly (because of all the extra junk it's catching) so watch your pressure gauge closely and don't be surprised if you have to backwash within 24 hours.

Good luck!

One other thing I forgot: put a skimmer sock over your skimmer basket. It makes a big difference!

 

[duraleigh]

Hi, Cindy,

Welcome to the forum. Posting up a set of test results would be very helpful. Just guessing, but based on your good narrative, I think you are experienceing dead algae dropping out onto the pool floor.

It means your pool is not yet free from algae even tho it may look clear. Swim down and gently pick up some of the "dirt" between you finger and thumb. If it is slimy and not gritty, it's dead algae. You need to shock.

Reread the section in Pool School on how to shock. Make sure you understand that it is a process rather than a one time dosage. Your shock process will be complete when....

1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.

I'm sure you'll have questions about this post.....ask away. Everyone here will work hard to help you get your pool absolutely pristine.

PS - I may be completely off base without test results but I suspect your filter has nothing to do with your pool issues.

 

[cmayes71]

My test results are:

Chlorine 7
Ph 7.5
CC 0
CYA 30
TA 140 (TA was checked earlier this week)
no chlorine loss in overnight test.

It was clean today until I turned my pump on high. Within one hour of turning the pump on high there was what looked like brown dirt in various spots all over the pool. I have vacuumed everything out and currently have the pump set to bypass. Since doing that no more dirt is depositing in the pool. Our pool is brand new. We just got it a couple of months ago. When I set the pump back to filter I'm going to see if the dirt or whatever it is returns.

I shocked for mustard algae because I assumed that was what it was. After getting in the pool and inspecting it, nothing was on the walls. The pool did not feel slick anywhere. When I brush the spots, on the surface of the water, is what looks like pollen.

I do have a knee high pantyhose on the skimmer basket. I've been thinking about adding DE.

Thanks

Cindy

 

[cmayes71]

Just a minute ago, I put a knee high stocking on the return with the pump off. My husband held it there while I turned the pump on high. Sand and stuff blew into the stocking. I don't know if one of the "fingers" could be broken or if it is channeled. My husband felt of the brown spots in the pool and they did not feel slimy.

When I used the aquabot earlier the bag was covered with sand and the inside of the bag was yellowish green.

We are having a pool party in a couple of weeks for my son so hopefully we can get the pool in pristine condition before then.

Thanks for the help.

Cindy

 

[Bama Rambler]

We have the same thing in our pool. In our case it's just dirt. Granted it's very fine dirt and the sand filter won't stop it. I have performed the overnite drop test several times just to be sure and never get any drop. I have toyed with the idea of adding DE to the filter but around here you have to buy 10lbs of DE at the time and I figure it'll only take a few cups at a time. I'll probably do it soon though because the dirt is relentless.

 

[duraleigh]

Cindy,

Since your pool is so new and apparently very clean, I wonder if your sand is not too full in the filter.

Generally, the sand is about 2/3 full on all sand filters.

You'd have to take the lid off, but it would be pretty easy to tell.

Cahnneling typically occurs from neglected pool water over a long period of time. Very unlikely that is the case with yours.

 

[Buggsw]

One more thing besides the excellant advice. Perhaps you shouldn't be backwashing every week. A filter works better when it is slightly dirty. So, don't backwash unless your pressure indicates you need to do so.

 

[Bob_Funk]

Are you setting the filter to rinse for a minute or two after back washing to settle the sand back down?

 

[cmayes71]

I do set the filter on rinse afterwards for a minute. Actually I did not begin backwashing weekly until the last 3 weeks or so. I will stop doing that. Tomorrow we will take the top off and look at the sand. We are having problems with pollen here in Tennessee lately. Today the pool water was very clear and sparkling however, there is some dirt/sand in the middle of the pool.

Thanks for the help. I will post back after looking at the sand level.


Cindy