Since I found out about the BBB method from the other Pool Solutions Forum I have followed it religiously and it has worked great for 3 years. So I think I will follow suggestion from several folks and add a cup of DE to the sand filter. Do any of you pool owners in Raleigh NC know if Rising Sun carries DE or have suggestion where I might purchase? Thanks
DE in sand filter
- Thread starter POOLGIRL
- Start date
Home Depot and Lowes both usually carry DE. Their pool departments are generally out near the plants, poorly stocked, and forget about asking for help, but the prices are good when they have what you want.
DE can remove VERY tiny particles, adding that sparkly polish to your water. When you backwash, you have to replace the DE, as it sits atop your sand, and is so light it just floats out!
When adding DE to a sand filter, it will probably take less than a cup. Add the DE very slowly (over the course of several hours?) through your skimmer until you get a 1psi rise in yout filter.
When adding DE to a sand filter, it will probably take less than a cup. Add the DE very slowly (over the course of several hours?) through your skimmer until you get a 1psi rise in yout filter.
Sand filters normally filter out particles down to about 20 or 25 microns. DE fitlers filter out particles down to 3 to 5 microns. By carefully adding a little DE to a sand filter you can partially clog up the pores in the sand giving you the 3-5 micron filtering, but you need to replace the DE every time you backwash. Getting the 5 to 25 micron particles, which would normally go right through a sand filter, out of the water give it a little extra clarity and sparkle. Some people refer to is as "polishing" the water.
Basically you check the presure of the filter, mix half a cup of DE with water and pour it into the skimmer, repeat additions until your filter presure goes up 1 lb. Once you know how much DE your filter needs you can add all of it in one step the next time. One or two cups usually does it. Keep in mind that DE particles are really small (ie get into the air really easily) and you don't want to breathe them in, so wear a resperator of some kind. The ones they sell for wood workers ought to be good enough and are easy to find.
Basically you check the presure of the filter, mix half a cup of DE with water and pour it into the skimmer, repeat additions until your filter presure goes up 1 lb. Once you know how much DE your filter needs you can add all of it in one step the next time. One or two cups usually does it. Keep in mind that DE particles are really small (ie get into the air really easily) and you don't want to breathe them in, so wear a resperator of some kind. The ones they sell for wood workers ought to be good enough and are easy to find.
Thanks! I will keep this in mind. If all goes well, (putting together the correct equipment package) then I will be ordering a pool next monday. So this is definitely something to keep in mind.
Again,
Thanks!!
Todd
Again,
Thanks!!
Todd
Many thanks for the detailed info on how to apply. I probably would have just dumped a cup in the skimmer.
Just to stir the pot a little, I have a mild degree of skepticsim about adding DE to a sand filter. I have tried it on two occassions and could detect no difference. I have anecdotal evidence from two others who have tried it with no detectable difference.
I realize many of you have done it with reported success but, somehow, the logic of it doesn't register with me. If the DE is fine enough to capture particles that pass thru sand, why doesn't the DE pass thru the sand as well? I admit to being inordinately skeptical but I wonder if any of the filter companies have ever done any research on this subject or if anyone has actually tested water clarity before and after DE?
POOLGIRL, I'm in Raleigh and have not seen DE in Lowe's or HD (still may be there, tho).....it's in all the pool stores I have visited.
I realize many of you have done it with reported success but, somehow, the logic of it doesn't register with me. If the DE is fine enough to capture particles that pass thru sand, why doesn't the DE pass thru the sand as well? I admit to being inordinately skeptical but I wonder if any of the filter companies have ever done any research on this subject or if anyone has actually tested water clarity before and after DE?
POOLGIRL, I'm in Raleigh and have not seen DE in Lowe's or HD (still may be there, tho).....it's in all the pool stores I have visited.
Thanks for info DURALEIGH. I may just pass on the idea since I would have to go to pool store and I already owe for repair visit. But I had to laugh when I saw the word logic in your post. There is absolutely nothing logical about my pool. I am sure I am the only person that has had their pool turn the most beautiful shade of PURPLE (at Easter 3 years ago no less). The only thing that has kept me from losing my mind is that I learned the BBB method.
duraleigh said:
Median particle size for swimming pool DE is 34 microns, which is plenty large enough to be caught by the sand filter. Assuming nothing else special, adding a little DE will make your filter work better, like a slightly dirty filter. The physical characteristics of the DE, with many small particle grabbing pores would seem to make it even better than that. IF the DE coats the sand bed in a uniform layer, it would be little different than a DE filter in that the sand is a just like the grids in a DE filter.
It would be interesting to add the DE to a sand filter, then to shut it down and remove the valve and see how the DE looks. I would suspect that it will not be in a layer, but rather at varying depths within the sand bed and not acting like a DE filter.
I'll add for folks unfamiliar with sand filters that I don't add anything to my sand filter and it keeps my pool water crystal clear. I have cattle on one side and a corn field and gravel road on the other.
I've actually done that and it does indeed form a pretty uniform layer on the top of the sand (zeo in my case) bed.JohnT said:
DE can be purchased at both Lowes and Home Depot plus Leslie's in Central Texas.
(31% Muriatic Acid, as well)
(31% Muriatic Acid, as well)
Clean sand will filter to about 60 microns. When it gets dirty it will filter to about 30 microns. Adding DE 'dirties' the filter and will not produce the 5-6 micron filtration a DE filter will since the DE can and will move between the sand particles. It will improve filter performance of a sand filter to a degree but it no way comes close to the filtration of a DE filter. Also, as sand ages and the facets on the sand become 'polished off' from the erosion of the constant flow of water it becomes less effective at catching particles and it's filtering ablility decreases. Sand's biggest plus is that it is the easiest type of filter to maintian. A cartridge will filter to about 20 microns clean and probably below 10 microns when it starts to get dirty and actually approaches DE's effectiveness at filtration, unless the cartridge has been acid washed. Acid washing a cartridge will cause the filter fabric to stretch and the pores in the material will become larger. (A cartridge is, IMHO, much easier to clean than a DE filter, which really should be broken down to be cleaned and not backwashed or bumped, but that is a topic for another thread!) The biggest drawack to a cartridge filter comes when they are undersized and the time between cleanings is very short, an all too common occurance! Also, as any filter dirties the flow rate will decrease which will make filtration less effective since it will take longer to filter the same amount of water so while you can increase the effectiveness in terms of size of particle filtered there is a diminishing return because it will take more time to filter and 'turnover' the water.
Last year I was doing some microbiology experiments on the pool. One experiment included taking a volume of pool water and concreting it by centrifugation. The experiment took about 5 weeks. I was concretizing the pool water to increase the ability to catch any possible pathogens in the pool. I used 2-60 cc conical tubes and concreted the pool water. I removed the supernatant and cultured, wet mounted, and stained the remaining material. At week 3 I added the DE and found my testing material had be cut by greater than 50 %. Under the scope the particle size had also dropped. The scope I was using did not have a micrometer so I can’t give particle sizes. There are gains using DE in your sand filter but you must weigh them with the need to run your pump longer as WaterBear spoke of.
BTW you don’t want to know what I grew in the water at the levels Nature 2 recommended at the time I bought my pool. Then again Nature 2 is one of my big rants.
Steve
BTW you don’t want to know what I grew in the water at the levels Nature 2 recommended at the time I bought my pool. Then again Nature 2 is one of my big rants.
Steve
tpg said:
tpg,
By now, are you sorry you asked??? :lol:
Seriously, I have enjoyed this thread and learned from it. My take from all this is, if you want absolutely the cleanest, most sparkling water in your town, adding a little DE might help and certainly doesn't hurt. However, dirty sand may just accomplish the same thing.
Since the cost of dirty sand is cheap and DE, regardless how inexpensive, would have to come from my beer budget.......hmmmm. :lol: :lol:
Nope, I am not sorry in the least!
It is something to think about though. I too have learned alot from this thread and am grateful for all that has been shared. Now I have read else where about people using "skimmer socks". How small of a particle do they capture?
It has been fun and interesting to hear people discussion the differences in the capabilities of the different filters systems. As a wood worker, I know that the 3 micron filter bags on my dust collector has made a big difference when compared to the old 30 micron bags that I had. This is how I have visualize the differences in these filter systems.
TPG
It is something to think about though. I too have learned alot from this thread and am grateful for all that has been shared. Now I have read else where about people using "skimmer socks". How small of a particle do they capture?
It has been fun and interesting to hear people discussion the differences in the capabilities of the different filters systems. As a wood worker, I know that the 3 micron filter bags on my dust collector has made a big difference when compared to the old 30 micron bags that I had. This is how I have visualize the differences in these filter systems.
TPG
Skimmer socks don't really trap the small stuff but they are great for keeping the bigger stuff out of your filter and they really do lengthen the time between filter cleanings. I have been using them for a few years and they are one inexpensive pool gadget that is really worth ten times the price that they cost!tpg said:
During pollen season they are easily worth one hundred times the price!
The way you visualize the dfference in filter systems is entirely correct. The only difference is that yours are filtering particles out of the air and your pool's are filtering particles out of the water.
waterbear said:
I would add life cycle cost to the advantages of sand filters. Cartridges ain't cheap and need to be replaced periodically. DE is an ongoing, regular cost.
When properly maintained a cartridge can last for 5-7 years. If it costs $100 that works out to $20 a year or less. Sand also needs to be replaced (I know this is an ongoing debate but look at new sand under a microscope and look at old sand and tell me which one you think will filter better, Much of the improved filtration ability of Zeolite is not because it has pores but because it is much rougher than sand so it can trap particles easier) Sand might actually only have a lifespan of about 3 years if the pool has an extended swim season and is not winterized, making sand about as costly as cartridge.KurtV said: