Added DE to sand filter. Now pool is full of DE.

[les_smith]

I added DE to my sand filter today to aid in filtration. I had a reading of 13.5 psi on the pump and added about 4 cups of DE to the skimmer. The gauge went to 15 psi and I stopped adding DE. I then got in the pool and started to vacuum. I use goggles and a snorkel and get under the water when I vacuum. To my surprise I saw the DE in the water. After a few minutes I went and looked at the pump and it was back to 13.5 psi. What's up? My sand filter has been working great. All I've had is a small amount of fine brown dirt type substance settling in the low spots of the liner. That's what I was hoping to catch with the DE. But, now the DE is in the pool. Again, What's up?

[les_smith]

After about 1 1/2 hours I went out to put a skimmer sock on the skimmer basket because I thought it might help catch some DE in case the sand was not catching any of it. Anyways, the pump was back up to 15 psi again. Also, I could see that some of the DE has settled to the bottom of the pool. Any clues as to what's going on?

[Poconos]

Sounds like the pump/filter combination indicates you're filter is too small and stuff is blowing by the filter. How about detailed info on the sand filter and pump. Would really help to diagnose this problem.
Al

[les_smith]

I have a 200lb Aquatools filter and a 1.5 HP Aquatools pump. The pump pressure is holding steady at 15 psi. Is there a chance that I added the DE to quick and some how it blew by the filter? If that is the case, how does something blow by the filter?

[CarlD]

You added FOUR CUPS of DE? I'm not surprised it blew into the pool! What were you thinking? I have a 200# Hayward and 1 hp SuperPump and I add less than ONE cup of DE each time I backwash!

Best way to get it out if it's on the bottom is vacuum to waste.

[les_smith]

I was going by the idea that you add DE until you get a 1 psi jump in the pump pressure. That's the way that I understood it from reading the forum. I went until it jumped 1 1/2 psi. So, If I added to much, how does the DE get into the pool? I thought it would have to go through the sand first. When Poconos mentioned "blow by" is there some sort of relief built into the filter so that something blows by the sand before the filter is damaged? I mean we're talking about 15 psi, I can create more than that putting my thumb over the end of a water hose.

[GraceByDesign]

When your pump is too powerful for your filter, it can blow 'stuff' right through the sand and into your pool. ('stuff' being dirt, filter sand, DE...)

[poolmom06]

I have a 100lb sand filter and a 1 HP pump and I just add about 1/3 cup of DE each time, I WAIT 20 minutes( per instructions here) and check the pressure, if it has gone up 1PSI then I am done. I rarely have to add any more... the first time I did it, I did the same thing kept adding and didn't see any result in PRSure rise, came back and read this site and did it right after that!!

[CarlD]

You could also try the following:
1) backwash to clear any DE out of the filter
2) Vacuum (not to waste) and see if the filter takes the DE or blows it out again into the pool (DE is MUCH finer than sand).
3) If it's still blowing out DE, repeat steps 1 and 2.

You have to WAIT until the pressure rises.

[les_smith]

So, I'm figuring that I added the DE to quick. The bonus is that pump pressure rose back to 15 psi which is 1 1/2 psi higher than when I started. I suppose that as the pump ran and circulated the water the DE was re-collected in the sand filter and the pressure rose back up. I vacuumed up what settled to the bottom of the pool and I'm going to assume that it is now sitting on top of the sand as well. I'll check tomorrow to see if anymore has settled to the bottom. If not, then I figure everything is good-to-go. If four cups is to much, then I look forward to experimenting to see exactly how much gives me a 1 psi jump in pressure. Next time I'll add it slower.

[medvampire]

I did the same thing the first time but I had added but only 2 cups. After trial and error I found I only need 3/4 cup added over a 1 to 2 hour peroid due to blow through of DE through my filter.
Steve

[aquarium]

If you haven't opened the multi-port valve in a while, you might check the spider gasket and see if it allowed that blow-by.

[les_smith]

Well I checked the pool this morning and the pump pressure was holding steady at 15 psi. So, the DE is working. There wasn't nearly as much DE settled at the bottom as there was when I put the DE in. The pump only runs 6 hrs at night, so I'm figuring there was plenty of down time for the DE to settle. I keep vacuum (not to waste) and see if the DE quites settling. Do you guys think that with the amount of DE I added that some will continue to blow by the sand? If not, I'll just wait and let it go until I do my next backwash and then re-do it with a smaller amount of DE.

[ThePoolGuy]

You added FOUR CUPS of DE? I'm not surprised it blew into the pool! What were you thinking? I have a 200# Hayward and 1 hp SuperPump and I add less than ONE cup of DE each time I backwash!

Best way to get it out if it's on the bottom is vacuum to waste.

I was going to say, I've never heard of adding more than a cup of DE to a Sandfilter.