Which way to add DE to skimmer ?

Jun 14, 2009
424
Cincinnati, OH
I've been told to add my DE to my skimmer in two different ways.

1) Dump the powder directly into the skimmer.
2) Mix the DE powder with water then pour the results into the skimmer.

Which way is correct, or do they have the same results in the end?
 
ALWAYS ALWAYS ALWAYS mix the DE into a slurry with water and SLOWLY pour that into the skimmer. If you don't the DE powder can clump up in your plumbing and make 'cement hard' clogs that are impossible to remove!

THIS IS NOT NEGOTIABLE!

Hope this answers your question. :wink:
 
waterbear said:
ALWAYS ALWAYS ALWAYS mix the DE into a slurry with water and SLOWLY pour that into the skimmer. If you don't the DE powder can clump up in your plumbing and make 'cement hard' clogs that are impossible to remove!

THIS IS NOT NEGOTIABLE!

Hope this answers your question. :wink:


What if you pour it through the skimmer basket? There is no chance for clumps as it has to get through the basket to get to the pipes. Mine mixes with the water that is in the basket and off it goes.

I do not want to advocate this as you made a pretty strong statement and you are a very knowledgable source of info on this board. I just don't see how it can clump together in the pipes if it goes through the basket first and gets mied with the water there.

Thanks,
John
 
waterbear said:
ALWAYS ALWAYS ALWAYS mix the DE into a slurry with water and SLOWLY pour that into the skimmer. If you don't the DE powder can clump up in your plumbing and make 'cement hard' clogs that are impossible to remove!

This is the response i got from the person who told me to mix it with water first.

But my pool guy told me to just dump it in through the skimmer/basket and it will be fine.

i see both sides of the question...

But i guess taking the extra step to mix it wont hurt anything where as if i just dump it in, in theory it could clump and cause issues.
 
I agree with Waterbear.

Even poured through the skimmer basket, the DE can still seem to "stick" together / group together after the basket.

If you are adding it when it's dry into the basket, it get's wet, goes through the basket and then it (at least to me) appears to stick to itself as it funnels down and (again at least to me) could clump together.

Just another thought. I prefer to mix into a slurry (which is consistent with the instructions on the box anyway).

Here's something for Waterbear that I've always wondered:

How come you cant just "dust a little" DE into a bag of sand when putting new sand into the filter for the first time?

Not that I would try it of course, but everytime I look at it in it's "powdered form", I always wonder whey you couldn't just mix a dry cup for example with 100lbs of sand in the filter. I'm guessing (when dumped in through the skimmer) it just kind of rests on top of the sand bed?

It would seem that a little amount throughout the sand would help a bit but to a novice like me, I'm sure that's too simple of an example. I'm sure I just don't fully understand the actual working of it but I'm always curious though.
 
If you ever had to break apart clumped DE you would understand. The stuff is like cement and it does that in your filter and it does that in your pipes! It's your pool so do what you want but don't come crying when you have plumbing problems. They happen. Pool guys are basically lazy and take the easy way and many of them don't even have a clue when they buy one! I've worked with ones like that in the past! I could tell stories but I'm getting off topic here.

The idea of adding DE in a slurry is that you are basically pouring in a milky liquid and NOT a thicker substance. When you dump it in the skimmer, even with a basket there, it is not dispersed in the liquid and is more of a 'cream' going through. This is what can lead to clogs. I have worked on commercial DE filters that used about 12-15 lbs DE powder after each backwash and they were backwashed daily! (There were two of them since this facility had two pools!) We would mix the slurry in a big bucket with a few scoops of DE at a time. It took a while. (And yes, I was wearing a respirator because DE would become airborne!)

As far as putting DE in with new sand, why? First, with new sand you don't need DE since it will filter very well. DE helps old sand filter better. Second, the first time you backwash you will wash out the DE and have to re add it (AND it is a good ides to backwash new sand until the water runs clear before putting the filter online so you WILL wash out any DE that you added with the sand). Third, you really don't know how much DE you need in a particular filter to get that 1 PSI rise in pressure so by putting it in dry can very well 'overdose' that particular filter.
 
Thanks Waterbear.


I never thought about the fact that new DE would wash right out (if it was mixed with the sand). That would make sense. And not knowing how much you would need to get the 1psi increase would also make sense.

Like I said, I never really thought about it.

I've always followed the directions on the box (as far as the is DE concerned). They must tell you to mix it into a slurry for a reason right?... and your comments that it's "concrete like" would make sense.

I just replaced the sand in my filter and I agree with you, It's amazing how much "dirt" and junk comes out of the new sand on that first backwash. I've heard of people not doing that when adding new sand and always wondered why.

On my older filters I used to add a layer of pea gravel to just cover the laterals and I would "pre-wash" the pea gravel. - Talk about dirty stuff!. Pea Gravel is filthy!
 
I am bumping my post, because i would like to make a point with a picture.

Don't put DE in as a powder, always slurry it up first.

Here is why.
When i took my filter apart today to clean, there were a few sections clumped up like this.

img0120x.jpg
 

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WestSidePool said:
I am bumping my post, because i would like to make a point with a picture.

Don't put DE in as a powder, always slurry it up first.

Here is why.
When i took my filter apart today to clean, there were a few sections clumped up like this.

img0120x.jpg

That is more likely DE that isn't backwashing out. Don't misunderstand me, I'm sure you backwash correctly, But the design of those types of filters inherently do this. I have never really liked that design for that reason. You get the caking of DE because of accumulation of new DE over old that did not get backwashed out. IMO the best DE filter design ever was the old spin filter type. You could agitate the grids (by spinning the grids) and could get virtually 100% of the DE off and out. Sadly as with alot of products, the best designs get discontinued. This one i think because the filter area was never very large. These days manufacturers like to go big.
 
Ok, this is old enough that I no longer think what I'm going to say will cause 'hostilities'.

As long as you have 2 suction lines pulling you can 'dry dump' the DE and get proper/ even coating on the grids :eek: :!: Here's what happens; the 'cream' from the skimmer line you dumped the DE in mixes with the non-DE water from the other line(s) to create ~ the same mix you'd get from making a slurry.

I know for a fact that this works because I've had reason to open a freshly 'dry dumped' filter more times than I'd care to remember and in every case, the grids have a nice even coating of DE on them :shock: :p

{edited for potential flaming by Ted}
 
My experience confirms what Waste has said above. I have two skimmers and a main drain. I add my DE dry to the skimmer closest to the pad with all three suction lines running. I add it slowly with basket in place. I have been doing it this way since 2004--it was the way the PB (AnthonySylvan) rep taught me to do it. I have had the filter opened up mid-season for other reasons, and coating was even and complete.

I am sure it is POSSIBLE to clump it up inside the pipes, if everything is favorable to having that happen (one line, pour too quickly, no basket, etc.) I also believe it is possible to AVOID having that happen by creating the correct conditions.
 
But you would not recommend dry-dumping for a single suction line (which is what I have)? When I bought the place and had a pool guy show me what's what, he didn't say anything about slurry. He did say to put it in slowly, and it seems if you do it slowly enough (and with basket in place) there's not going to be much opportunity for clumping.
--paulr
 
This is a bit off topic but still in context. Recently I switched to cellulose for my DE filter. I've always had to backwash very frequently in past using when using DE because of too small a filter, 36 sq ft, for the amount of stuff that gets deposited in my pool, although it is almost entirely silt/mud/sand that makes it to the filter. (I'm up-sizing filter very soon).

This may be coincidence, as the puppies aren't in and out of pool as much, and we've had lots of rain so blowing silt is cut way down, but for weeks now I have been dumping the cellulose, 6 scoops, into skimmer all at once, as per instructions on bag, with main drain open too. It would take a long time for the cellulose to make it to the filter and and actually would create a "filter" in the skimmer. If I didn't help it by sniffing some of it around every few minutes it would take a few hours for all of it to make it out of the skimmer. I don't think it was evenly coating the filter, though, as I went way beyond the period where instruction said "filter will have shorter run time cycles for a period after switching to cellulose". Until this last backwash I was having to backwash 2-3 times a week because of very fast increase in psi AND I wasn't seeing better filtration as it seemed that I had a lot more fine particulates in water, most easily seen at night with light on, than before when I was using DE.

This last time I added one scoop, let it totally leave skimmer, add one more, etc,. I've now gone three days with only an increase of 1 psi, running the filter 24 hours all three days. And the water hasn't been this clear in ages.

So, in the case of cellulose, in particular, to get even coating the media has to be allowed to thoroughly mix/blend with water, by what ever measure, before it gets to the filter otherwise it probably won't coat evenly.

I, too, think that with DE the main factor is having the DE thoroughly blended with water prior to entering the filter is the main issue, no matter which way it is achieved. I've used the dump-dry-into-skimmer, with main drain open, for 23 years and never had any issues, other than making sure the pump pot has no debris in it when adding the DE (only had that happen once at very first but learned my lesson). I've maintained exceptionally clear water, even with the vast amounts of silt, with only a few exceptions (out of the ordinary circumstances), for 23 years and have always used the dump-dry-into-skimmer method. Even with my way over-sized pump, my grids last as long as "expected" too.

BTW.... the only "choked" pipe I've ever had was due to small rocks mixed with silt and organic debris, getting into main drain when the drain cover was off (don't ask :oops: ), one winter when I had to leave country, abruptly, for a month, in late December, a critical time to keep muck out of pool, and had to shut down pool, not properly closed, in the middle of doing some work on it. Of course I returned to a developing swamp with several feet of leaves, mud, other objects blown in, a couple of dead rats (discovered when I did spring clean up). It took me a couple of years to finally get the semi-blockage cleared, and that whole issue was not related to DE. BTW... my pumping station is below level so there is a great deal of water pressure to station even from the main drain.

I'm no expert, by any means, but I do know my pool and have done all the maintenance, and most "fixes" on it for decades.

gg=alice
 
Pool Clown said:
That is more likely DE that isn't backwashing out. Don't misunderstand me, I'm sure you backwash correctly, But the design of those types of filters inherently do this. I have never really liked that design for that reason. You get the caking of DE because of accumulation of new DE over old that did not get backwashed out. IMO the best DE filter design ever was the old spin filter type. You could agitate the grids (by spinning the grids) and could get virtually 100% of the DE off and out. Sadly as with alot of products, the best designs get discontinued. This one i think because the filter area was never very large. These days manufacturers like to go big.

I agree. I've always done all the maintenance on my equipment and pool. There is usually some clumping, in ordinary circumstances. In unusual circumstances the clumping has been so bad I wonder if any water could be filtered anywhere but the outside grids. I'll find and post an embarrassing picture.

I have only a push/pull valve but I've discovered a process that somewhat simulates the rinse cycle using multi-valves that does seem to clear some more of the between the grids DE out during the backwash process. For those who don't know, I've been backwashing my 36 sq ft DE filter, weekly, for 23 years. Don't want to explain it now but will be glad to post if anyone needs the info. May have to wait as I do it kind of automatically so I'll have to take notes next time I backwash.

Since I've been researching DE filters (have a great need to up-size filter) I've discovered I do have options other than the vertical, curved grid, type. That's why I'm so interested in getting the Pentair Quad DE even though Pool Store has offered me a greatly reduced price on a vertical grid Hayward (floor display).

Pool Clown, I've made a few attempts on board to get some opinion from anyone, especially someone with experience who can make comparisons, on the Pentair Quad and others. I really, really, want to pick it up at warehouse this week and get it installed before it gets colder. I'm so glad you said you don't like the vertical, curved design. Just helps to confirm my feelings and observation. Please comment. :-D

gg=alice
 
waste said:
Alice, you are wise beyond your tender years to avoid the discounted Microclear filter! Please see this thread. I'm sure that what they're trying to sell you is the obsolete model (just another way to be pool stored :p )

Have fun with the new filter :-D

It is the 6020 or 2060, anyway 60 sq ft. As stores were offering the multi-port valve, included anyway, trying to off-load the "obsolete" filters, that makes the pool store offer not as sweet AND manager was not telling me the truth, if he knew about the "problems" with the filter. Maybe he didn't. I'm going to give him the benefit of doubt though, as I'm a way too forgiving person. He told me that corporate had instructed them to use a smaller filter in the display, and he didn't know why.

Thanks Ted, for the heads up. :goodjob: I now remember reading your post about that (and just reread). The Pentair Quad is a pretty new release, I think Spring 09, but not positive. There are other filters with similar design using cartridge and DE, aren't there? Just want to make sure there is some in-field experience with similar designs. In my opinion, I think the price of the Quad 60 is pretty reasonable. The warehouse knocks $75 off the price if you pick it up locally. Of course I'll have to pay taxes, but still less than most other prices plus shipping I've seen on internet.

Only bummer is having to dig out a 24" deep "hole" (for vertical clearance) and then reinforce sides and pour pad, and then make a drain in pad leading about 15' down the hill. Going to do rigid 3" or more PV inside the black flexible pipe used inside french drains, etc., to protect the pipe from all the rocks in soil. It's about 80% rock/20% "soil" down there. I'm even considering just digging the hole and using an 18" concrete "paver" I have, temporarily, until next spring. It's under the deck so not a lot of water gets down there to wash-out the hole. Extra bummer is I can't stand up under there. Everything has to be done either on knees or bent over, which quickly stresses anyone's back. I get the most complaints from younguns :roll: who have worked under there. And I will wear one of my hard-hats as the decking support is steel, with some L bars in critical places. More people, than I like to report have gashed open their heads under there. Once was enough for me but some people are too hard headed (but not enough to prevent injury) to listen to me. :hammer:

Referring to your linked post ... I have a friend, who worked for a company, in Dallas area, that makes gaskets, o-rings, and many other things like that. He no longer works there and has moved to upstate NY. He made several replacement gaskets for my ancient, giant pressure cooker over the years. Sure was a handy friend to have around.

gg=alice
 
geekgranny said:
Pool Clown said:
Pool Clown, I've made a few attempts on board to get some opinion from anyone, especially someone with experience who can make comparisons, on the Pentair Quad and others. I really, really, want to pick it up at warehouse this week and get it installed before it gets colder. I'm so glad you said you don't like the vertical, curved design. Just helps to confirm my feelings and observation. Please comment. :-D
gg=alice

I say, if you want it, go and get it. Who am i to tell a Grandmother not to get what she wants. At the very least, we will have this new filter out there in the "Test environment" for you to report back on its performance, good or bad.

I hope the clearance your digging out for is for clearance to take the tank apart (you will need to lift the top half of the tank vertically to clear the elements), as well as clearance for the tank itself (of course).

If you buy this filter on-line, you may be able to find a site that will give you free shipping (to your door) and or tax!

Note: I did not mean to imply that the vertical DE filter is a bad design from a performance stand point, but that the backwash design/performance had much to be desired.
 
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