DE does not coat filter grids

[gzh]

Hi,

I am in Maryland. I am struggling to understand an issue with my filter that I started to have near the end of last swim season. The issue is that D.E. powder does not stick to my filter grids! I opened my pool last week and I have started from scratch twice using D.E. from two different manufacturers, first with a product bought from Leslies and then a product brought from WaterCrafsters. No difference. When I opened the filter tank I still see no coating on the grids.

Then today I noticed one thing. After the pump stops, white powdery water comes back to the pump (I can see it through the clear window) and goes slowly all the way back to the skimmer (I only have one skimmer). I don't remember I saw this when I had no problem with the pool. I don't know if these two are related.

I asked Leslie's and a local pool service store WaterCrafters and they didn't seem to know why DE wounld not stick to the grids either.

I don't want to run the filter without the grids properly coated with DE.

Anyone knows what is going on here? I am starting to get frustrated.

Any help is greatly appreciated.

John

 

[Richard320]

DE falling off the grids isn't so bizarre, but it shouldn't be flowing backwards.

I'd look for a lot of air trapped in the filter (that's why there's an air bleed on top) and then see if the check valve is stuck - or was never installed.

 

[gzh]

Richard320,

Thanks for your quick reply.

I also thought of air inside the filter tank. What I did to ensure that air is out is that I opened the relief valve on top of the filter until water comes out. I also can tell there is no more air inside the filter by gently tapping the top - you can tell the difference when there is no air.

What I understand is that after fresh DE is added, it would coat the grids within half hour or so. Once the grids are coated the DE will stay on them unless it is hosed off. I left the pump run over night twice and i still not see D.E. coating.

The O-ring may be a problem. When the pump is running there are tiny drops of water dripping out - like a drop a second or or so. When the pump stops for hours, I can tell lot of air gets inside the tank. It could be a problem. But this still does not explain why DE would not stick to the grids.

Any help is greatly appreciated.

John

 

[waste]

Welcome to TFP!!

Have you read teh 'Use and Care for DE filters" in the Further Reading section of Pool School?

 

[gzh]

I did not see it. I just signed up today. Thanks a lot for pointing me over there. I read the article. Based on the article I might have missed one thing: I added DE before I made sure no air was in the tank. I will do it all over again. Thanks. I will report back to see how it goes.

Thanks again.

john

 

[carlscan26]

Do you have a variable or two speed pump? Are you running on low speed with your pump? You need to run a high speed for 20 mins or so when you first add the DE to make sure it coats the grids. What model filter do you have?

 

[gzh]

I am pretty sure my pump has only one speed. I am not quite sure what model my filter is. I bought the house two years ago with the pool. What I can tell is the pool was built by Blue Havens and all equipment appear to have "Blue Havens" on it.

By the way, after I read the article recommended by Ted from Luv&Luk I cleaned up the filter and started from scratch again. I have the filter a couple of hours but I have not opened the filter tank yet so I don't know if the filters grids were coated properly. I will you all how it went when I open the filer.

Thanks for your response.

 

[chriscard25]

Well,

I have no air leaks, run my two speed 1.5 hp pump on high for about ten minutes when adding new DE, and Lowtherafter, and never see any DE on the bottom 2/3 of the grids when I clean it once a month, but quite a bit sitting at the bottom of the filter. I always assumed the clean DE falls, and this was normal.

 

[carlscan26]

I imagine a good bit will fall when you pop the filter off. The fiber clear stuff falls every time - thats something that turned me away from it as I don't see my pump on low speed stirring that stuff up enough to properly coat the grids (cartridges in my case). But that seems weird to be happening with DE. How old are your screens? Have you acid washed them without doing the tsp treatment first? Stuff like this makes me wish all filters had a view strip like the one in the fiber clear video lol

 

[chriscard25]

My grids have about 2 months on them--brand new.