De In Sand Filter Ok?

[mhugues]

I have a 38 X 16 fiberglass, around 16 to 18 thousand gallon. Nails were accidentally dropped in the pool and large rust stains developed. I put oxalic acid in a sock and set it on the stains. This is when I realized how stained the rest of my pool was. The clean white circles began to appear around each sock so i decided to clean the pool by taking the sock and wiping down the walls and setting them in different locations throughout the pool. I began to think this could be a dumb idea since I was in the pool with the acid. I then decided to just throw some acid in the pool and let it do the work. The pool has been cloudy ever since (3 days) so after reading a few posts I went ahead and put about a cup and a half of DE in my sand filter (yesterday). The pool looked very clear this morning so I decided to vacuum. I pulled up the Polaris which was covered with a fine white silt that is almost silky to the touch. After stirring up the pool with the vac it is once again cloudy. My question is this. Is it DE that is making it cloudy? Are the DE particles so fine that they get through the sand? Sorry about the long story but I just wanted to open myself up to get blasted. Thanks in advance, ~mike

[waterbear]

What you are seeing in your pool and what made it cloudy is most likely calcium oxalate that precipitated out when you put in the oxalic acid. IMHO, ascorbic acid is a much better solution to stains in fiberglass pools than oxalic acid. Vacuum as much of it as you can to waste. DE is often used in sand filters as a filter aid and, unless you have broken laterals in your filter, should not end up back in the pool.

[mhugues]

Thanks Waterbear. Do I need to vac to waste because it will return to pool on a regular vac? Is calciom oxalte even finer than the DE? Are the 2 products working their way through the sand and getting back in the pool or will the filter eventually clear things up? I am in no real hurry and would just as soon let the filter do it if it is capable. I was thinking of just keep swimming and increase the main drain pull to help clean it up. Thanks again, Mike

[Woodsy]

I was under the impression that you didn't want to use DE in a sand filter. However a product like a cellulose fiber could be used because it is biodegradable. Any insight?

[waterbear]

You don't want to use DE in a cartridge filte since it will plug up the Reemay polyester filter material and cellulose fiber is a better choice but DE works great in a sand filter as a filter aid. You want to add about half a cup at a time in a slurry to the skimmer and wait about an hour between additions until you get a 1 psi pressure rise. You now know how much DE to add to your filter and can just add the whole amount next time. It will be removed with each backwash. It is particularly effective with older sand that has lost it's sharp edges because of water erosion.

[Woodsy]

waterbear, I don't mean to sound contradictory to your DE in a sand, but I have some mechanics that say it clogs up the sand filters as well. If it works in your neck of the woods and have seen no trouble that is fine. I still will suggest the cellulose fiber as a filtering aid.

[waterbear]

waterbear, I don't mean to sound contradictory to your DE in a sand, but I have some mechanics that say it clogs up the sand filters as well. If it works in your neck of the woods and have seen no trouble that is fine. I still will suggest the cellulose fiber as a filtering aid.

Please post them and their source if you would.

[muss08]

DE in sand filter is fine, however, i've found that if left in the filter for too long the DE will mix with the sand and become very thick, sometimes clogging it up. I had a client put DE in a sand filter (for some reason) and did not backwash his filter ALL SEASON while adding a small amount of DE biweekly. When I went to close he mentioned bad flow. Problem pointed to the filter and when I went to replace the sand every internal piece of plumbing was full of DE and a small amount of sand.

[waterbear]

DE in sand filter is fine, however, i've found that if left in the filter for too long the DE will mix with the sand and become very thick, sometimes clogging it up. I had a client put DE in a sand filter (for some reason) and did not backwash his filter ALL SEASON while adding a small amount of DE biweekly. When I went to close he mentioned bad flow. Problem pointed to the filter and when I went to replace the sand every internal piece of plumbing was full of DE and a small amount of sand.

Well, anything done wrong is going to cause problems. The correct way to put DE into a sand filter is to add just enought DE to cause a 1 PSI pressure increase. When, and only when, the filter is backwashed and the old DE washed out is it ok to put more DE powder in!

Sand filters need to be backwashed when the pressure rises 8-10 lbs over the initial pressure. If they are allowed to go for a long period of time there will be problems, DE or no DE in the filter!

[Woodsy]

waterbear, sorry for the long wait, I have been very busy transfering stores and working long hours. I discussed this with a few other mechanics. They said it can be done but very little use is the only way. Too much use can start to clog as the other poster mentioned. Sounds like something only professionals that understand the consequences can do properly. For liability issues I won't mention DE use in a sand filter but will appreciate the advice if I ever decide to branch out on my own. Thanks.

[waterbear]

waterbear, sorry for the long wait, I have been very busy transfering stores and working long hours. I discussed this with a few other mechanics. They said it can be done but very little use is the only way. Too much use can start to clog as the other poster mentioned. Sounds like something only professionals that understand the consequences can do properly. For liability issues I won't mention DE use in a sand filter but will appreciate the advice if I ever decide to branch out on my own. Thanks.

You underestimate many pool owners. They are a lot more savvy than many in the industry give them credit for. I find many industry 'professionals' are the ones lacking in true knowledge! (And yes, I do work in the industry) If you check out two other very popular pool forum boards (poolforum and troublefreepool) and ask about who is using DE in a sand filter as a filter aid and what is the proper way to do you you might be very surprised! Using DE as a filter aid in sand filters is a trick that has been around for many years. It needs to be done properly or there will be problems, you are right about that, but isn't that true of just about any aspect of pool care?

[poolyeti]

As a pool service company, we routinely recommend adding a small amount of DE as a sand filter aid. We haven't had any customer complaints about it yet!

[waterbear]

Woodsy, do you by any chance work in a pool store that sells celulose DE replacement? (I know it's a high ticket item compared to DE because we carry it!)

[Woodsy]

Yeah I do. That is one of the reasons I am here. I want to be able to provide my customers with the best information I can. Certain training manuals say never to use it. Most of the time I wonder if the training manuals say something to keep the company from being liable. Probably the main case there. Also, we do carry both DE and the cellulose fiber. I have had a lot of people start using the cellulose fiber in their DE filter and find it works a lot better and very happy with the results.

I heard that California is getting rid of even being able to use DE anymore because it does contain silica(carnicagen,sp?). Anybody confirm this? If this is true, I am sure Arizona will follow.

[poolyeti]

I heard that California is getting rid of even being able to use DE anymore because it does contain silica(carnicagen,sp?). Anybody confirm this? If this is true, I am sure Arizona will follow.

If DE is a carcinogen ( Woodsy) then these guys are in serious trouble.....

[greg340]

I heard that California is getting rid of even being able to use DE anymore because it does contain silica(carnicagen,sp?). Anybody confirm this? If this is true, I am sure Arizona will follow.

If DE is a carcinogen ( Woodsy) then these guys are in serious trouble.....

Well this says alot....

"We're not allowed to call it "safe""

[waterbear]

DRY DE powder, if inhaled in large quantities, can cause silicosis (as can any finely ground silicon sand or dust). It does not contain silica...it is silica. It is the dried skeletal shells of prehistoric, one celled plants called diatoms. Proper precautions when handling it are all that is needed (wear a paper mask!) Not really different than any other pool chemical. Personally, I'd rather handle DE than muriatic acid but you don't see people trying to ban that (or are they?) Once you have the perspecitive and remove the loaded term 'carcinogen' (the LOVE to throw that one around, don't they) it becomes almost a non issue, doesn't it? The problem with things being banned stems mostly from politicians who do not have an understanding of science legislating on such matters. As an example I give you the ban on backwashable sand and DE filters in many areas. Cleaning a cartridge filter is certainly just as water intensive and if the concern is about 'grey water' I would be more concerned about the grey water that comes out of our washing machines,, showeres, dishwashers, etc. daily then about the amount that might come from our pool filters every few weeks!

Woodsy, as one 'pool store guy' to another (And I'm going to guess you work in a Leslies) our job is to sell our customer's as much stuff as possible each time they come in. Not all of us agree with that philosophy but it's the truth. Most pool store clerks are clueless and a large majority of them have probably never even owned a pool or kept one, IMHO based on the amount of misinformation that is commonly repeated. There are a lot of things that are entrenched in the pool industry that just don't hold up when examined scientifically!

Case in point, slugging acid to lower TA. Total fallicy. Doesn't matter if you slug it or dilute it. Lowering pH lowers TA. Period.

OR how about selling customers with cartridge filters trichlor? Their pools become overstabilzied and then we tell them to drain and refill. Why not just sell then sodium hypochlorite--liquid chlorine? (Cal hypo will cause calcium hardness to increase and they are in the same drain and refill problem). Lithium hypochlorite is too expensive for practical use!

How about laundry bleach. Most pool store guys will tell their customers that bleach is bad for their pool or that it will increase TDS (another bogus measurement--it's not the total amount of ionic material in the water that is important but what the ionic speicies are)! It's sodium hypochlorite! NO DIFFERENCE except in the amount needed to reach a certain ppm FC. Laundry bleach is either 3%, 5.25%, or 6% with the last 2 being the most common. Pool and/or spa liquid chlorine/shock is either 6%, 10%, or 12.5% with the last 2 being the most common.

I'll get off my soapbox now but I hope it's opened your eyes a little since I suspect you are relatively new in the industry and don't have a lot of practical pool experience (I appologize in advance if I am wrong but anyone who has ever owned and taken care of a pool knows that the advice from pool stores just drains their wallets and does not solve their pool problems.)

To get back to your question as to why certain training manuals say not to use DE as a filter aid...it's dirt cheap (no pun intended). If people used it to increase their filtering ability they would have no need for the EXPEN$IVE polymeric and chitosan based clarifiers that most pool stores love to sell (and that are, in most cases totally unnecessary!) or by selling the expensive and higher profit cellulose fiber filter aid. It'a all about the bottom line!

Tell me how pool stores justify selling baking soda at the ridiculously high prices that they do. (Bioguard dealers will tell you that their alkalinity increaser is sodium hydrogen carbonate and not sodium bicarbonate--these are two different names for exactly the same thing--baking soda!)

If the water is cloudy or foamy there is a water balance issue. Clarifiers and defoamers are not the answer, they only mask the symptom. If you fix the problem the water will no longer be cloudy or foamy. As an analogy, if your dog makes a mess on the rug you can spray it with a deoderizer so it doen't smell anymore or you can clean the mess up and solve the problem.

Just some food for thought.

[poolyeti]

Waterbear, I agree with a lot of what you said above about the misinformation that's passed on in a lot of pool stores. The philosophy that we have at the company that I work for is to give the customer the simplest, most cost-effective solution - even if that means talking them out of something expensive that they think they need! We think that customer loyalty and good word-of-mouth advertising is much more valuable than the short-term profit of selling someone pricey junk.

[hotspringer]

Common chemicals in proprietary products has always been a money maker for industry.

I assume the DE you're using is common 'floor dry' from the auto parts store?? It's much cheaper than the DE from the garden supply store, and even they are probably cheaper than the pool supply store. All of them will be cheaper than a one ounce package of roach killer and it's all the same Fuller's Earth mined around my old hometown. It'll take the blue out of blue jeans and the red out of off road diesel fuel, too.

I've seen Bentonite sold by the thousand ton barge load and then seen a quarter ounce of it in the health food store for $9.99!!

[waterbear]

Common chemicals in proprietary products has always been a money maker for industry.

I assume the DE you're using is common 'floor dry' from the auto parts store?? It's much cheaper than the DE from the garden supply store, and even they are probably cheaper than the pool supply store. All of them will be cheaper than a one ounce package of roach killer and it's all the same Fuller's Earth mined around my old hometown. It'll take the blue out of blue jeans and the red out of off road diesel fuel, too.

I've seen Bentonite sold by the thousand ton barge load and then seen a quarter ounce of it in the health food store for $9.99!!

DE and Fuller's Earth are not the same thing. Fuller's earth is a clay material such as found in kitty litter or 'floor dry'. It is compromised of several different speicies of magnesium and calcium compounds and is very high in magnesium oxide and calcium carbonate. Diatomaceous Earth is the fossilized remains of a one celled algae and is mostly silica. Apples and Oranges!

[ParagonPool&Supply]

Waterbear, I agree with a lot of what you said above about the misinformation that's passed on in a lot of pool stores. The philosophy that we have at the company that I work for is to give the customer the simplest, most cost-effective solution - even if that means talking them out of something expensive that they think they need! We think that customer loyalty and good word-of-mouth advertising is much more valuable than the short-term profit of selling someone pricey junk.

amen brothers...cause you know what???when people realize you're not some snake in the grass trying to bone them they trust you, and when you gain their trust and someone asks them who helps them out with their pool, well, I guess you all know the rest of the story...

I once said "every dog has his day" when I confronted this shady builder that not only ripped me off (as a subcontractor) but alot of the people he built pools for...and while I said this, he laughed in my face....well two months later after a Sheriff showed up at his house I got my money...about a year later he got audited after someone he screwed (who paid him in cash) let the IRS know that he paid him $100,000 for the pool in his backyard...and about every high-end homebuilder around here dropped him because he had screwed up so much crap at every job...and then guess who came in and did the repairs and got the service contracts???

the golden rule reigns supreme

[steve haigh]

hi, i've been reading this with great interest because i recently filled my pool and there was a lot of fine (but visible) particles floating in the water. after running the pump for a couple of days, it was obvious that my sand filter was doing nothing to catch the particles.

so, after reading this thread, i bought some DE and fed it into the skimmer to try improve the filtration. the DE came flying straight back out into the pool, the filter didn't seem to hold on to any of it!

I've checked the filter sand, it's .6mm as per manufacturers specs but the filter is about as useful as a leaky tea strainer!

so my question is, how to make the DE stick in the filter or in general, improve the filter performance?

one idea i have is; i have easy access to very fine white powered sand on the beach below my house. would it make sense to put a thin layer of fine sand, maybe 1-2cm on top of the .6mm sand then layer some DE on top of that? would that clog the whole thing? any ideas?

thanks, steve

[waterbear]

check the laterals in your sand filter. They might be damaged.

[steve haigh]

check the laterals in your sand filter. They might be damaged.

is that the plastic tubes at the bottom? wouldn't i need to empty the sand first?

i know the filter is working, when i backwash its plenty dirty, i'd just like it to work better.

[poolyeti]

check the laterals in your sand filter. They might be damaged.

is that the plastic tubes at the bottom? wouldn't i need to empty the sand first?

i know the filter is working, when i backwash its plenty dirty, i'd just like it to work better.

Yes, those are the tubes in the bottom. The only other reason that would happen would be if the filter valve was in the wrong position when you put in the DE. If you don't want to mess with taking all the sand out of your filter, and you feel pretty confident that it's working, then you could try a flocculant.