What we have is listed as "Food Grade" and says that it is safe for human and pet consumption so I would think as well as for pool use but I suppose that I can hold onto that for use in the garden and just go get some of the cheaper stuff from Lowes for the pool.
10 years into it, and just now trying TFP Method to fix the swamp
- Thread starter Luclin999
- Start date
What we have is listed as "Food Grade" and says that it is safe for human and pet consumption so I would think as well as for pool use but I suppose that I can hold onto that for use in the garden and just go get some of the cheaper stuff from Lowes for the pool.
Lost a lot of chlorine again last night, down to 12-14ppm this morning. I suspect though that some of that is due to all of the rain that we had here yesterday (three inches worth + what I diverted into the pool).
In goes more bleach..
In goes more bleach..
Day 9
Not too much of a change from yesterday. Maybe a little bit clearer but hard to tell.
Not too much of a change from yesterday. Maybe a little bit clearer but hard to tell.
- May 22, 2013
- 2,796
- Pool Size
- 12000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Thanks Yeggim, I remember reading that somewhere and it made me re-check what I had from FleetFarm. Worried me as I can never pull it up under "Pool" anything with their sites search.
It is marketed by a pool supply company, AquaChem and is sintered for use in pools.
And I was mistaken, it's a 24lb box.
It is marketed by a pool supply company, AquaChem and is sintered for use in pools.
And I was mistaken, it's a 24lb box.
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Ok, all this talk about DE made me curious and so I did a bit a checking..
~ Food Grade DE is made from freshwater critters and is considered safe for human and pet consumption as well as as an insecticide HOWEVER it is also much, much finer (smaller particle size) vs. pool grade DE.
~ DE used in pools comes from other sources (generally deposits of fossilized salt water critters), has a higher silica content, is heat treated, and has a larger particle size. This type is NOT for consumption and doesn't work well as a pesticide due to the larger particle size.
Because of the difference in the size of the particles, food grade DE generally does not work well as a filtration media (now I know) HOWEVER it can be used in combination with pool grade DE to help improve overall filtration quality even further.
How?
By adding it AFTER adding the pool grade DE.
The food grade DE is so fine that on its own, it passes through a DE filter's grids or the sand in a sand filter.. (Doh!) However, it ~is~ trapped by pool grade DE which means that it can be used as an enhancer for DE filters in much the same way that Pool grade DE can be used to enhance sand filters and it is actually marketed that way as a "DE filter enhancer" in some pool stores. Used this way it can trap the ultra tiny particles which are so fine that even pool grade DE can miss them.
So bottom line, no more food grade DE into the filter UNLESS it is goes in AFTER the pool grade stuff has been added.
Thanks Yeggim, without your comment I never would have started looking into this and doing the research into DE types.
So, back out I go to pick up some pool grade DE.
~ Food Grade DE is made from freshwater critters and is considered safe for human and pet consumption as well as as an insecticide HOWEVER it is also much, much finer (smaller particle size) vs. pool grade DE.
~ DE used in pools comes from other sources (generally deposits of fossilized salt water critters), has a higher silica content, is heat treated, and has a larger particle size. This type is NOT for consumption and doesn't work well as a pesticide due to the larger particle size.
Because of the difference in the size of the particles, food grade DE generally does not work well as a filtration media (now I know) HOWEVER it can be used in combination with pool grade DE to help improve overall filtration quality even further.
How?
By adding it AFTER adding the pool grade DE.
The food grade DE is so fine that on its own, it passes through a DE filter's grids or the sand in a sand filter.. (Doh!) However, it ~is~ trapped by pool grade DE which means that it can be used as an enhancer for DE filters in much the same way that Pool grade DE can be used to enhance sand filters and it is actually marketed that way as a "DE filter enhancer" in some pool stores. Used this way it can trap the ultra tiny particles which are so fine that even pool grade DE can miss them.
So bottom line, no more food grade DE into the filter UNLESS it is goes in AFTER the pool grade stuff has been added.
Thanks Yeggim, without your comment I never would have started looking into this and doing the research into DE types.
So, back out I go to pick up some pool grade DE.
- May 22, 2013
- 2,796
- Pool Size
- 12000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
rodog123
0
Howdy Neighbor checking in from Pearland here on the south side. Make sure to call the city of houston water department and let them know if you decide to re-fill your pool. If you let them know they will not count the months excessive gallons usage to your average daily usage.
According to the CoH water department, they no longer offer that credit.
Couldn't find any pool grade DE so I settled for some cellulose DE substitute. Just backwashed the filter and added six cups of the stuff into the intake to get the pressure up.
It will be interesting to see how well it works.
It will be interesting to see how well it works.
Here's my experience with DE and a sand filter. I don't use it until I can see the bottom. Until that point I'd rather have maximum velocity out of the returns (pointing down) to keep thing stirred up. Once I see the bottom, I only use it before vacuuming. After I vacuum, I immediately backwash. I haven't found DE to speed things up before that point. Don't sacrifice circulation for enhanced filtration early on in a SLAM.
Sand filters are slow but they will get the job done. Here's a few pics of sand filtration without any addition of DE except when vacuuming a few times at the very end.
As it stands, my turnover rate with the pump/filter setup I have is roughly 3.2 hours which is already pretty fast so I am not really that concerned with the turnover time increase of 10-15%.
More than anything at this point I am curious to see just what effect the DE will have on filter pressure and clarity over the next 4-6 hours (I'll backwash out the filter no matter what before I go to bed).
More than anything at this point I am curious to see just what effect the DE will have on filter pressure and clarity over the next 4-6 hours (I'll backwash out the filter no matter what before I go to bed).
Day 11
Not much change since Tuesday. ~Slight~ improvement to clarity. I think I can see the vague outline of the third step in the photo (but I could be imagining it
Been having a lot of rain over the past two days (with more on the way later this afternoon) which has been making getting accurate readings very difficult. Have been compensating by adding an extra couple gallons of bleach over what I *think* the pool needs.
Adding the cellulose to the filter did cause the pressure to rise up a few pounds over roughly 10 hours (from 12 to 16) yesterday but haven't really seen any noticeable improvement in filtration when using it over not.
Not much change since Tuesday. ~Slight~ improvement to clarity. I think I can see the vague outline of the third step in the photo (but I could be imagining it
Been having a lot of rain over the past two days (with more on the way later this afternoon) which has been making getting accurate readings very difficult. Have been compensating by adding an extra couple gallons of bleach over what I *think* the pool needs.
Adding the cellulose to the filter did cause the pressure to rise up a few pounds over roughly 10 hours (from 12 to 16) yesterday but haven't really seen any noticeable improvement in filtration when using it over not.
There definitely has been a slight improvement to the clarity today because this evening before sunset when I was brushing the pool was the first time that I have been able to see the faintest of shadows where the light fixture is located under the diving board when there was no hint of it at all earlier this morning.
Day 12
Very weird. No significant change in overall clarity of the water but after having virtually no change at all for over a day, overnight the filter pressure shot up 12 PSI in nine hours with no DE or cellulose added (I had already backwashed that stuff out two days ago). So maybe I'll start seeing some improvement in the next 24 hours.
Just backwashed it and pressure returned back to the 12 PSI starting point.
Lost very little chlorine last night as well.
Last night
FC: 24
CC: 1-1.5
Today:
FC: 22
CC: 1
CYA: 45 -50 (seems to have dropped a bit from the backwashing + rain we have had.)
Very weird. No significant change in overall clarity of the water but after having virtually no change at all for over a day, overnight the filter pressure shot up 12 PSI in nine hours with no DE or cellulose added (I had already backwashed that stuff out two days ago). So maybe I'll start seeing some improvement in the next 24 hours.
Just backwashed it and pressure returned back to the 12 PSI starting point.
Lost very little chlorine last night as well.
Last night
FC: 24
CC: 1-1.5
Today:
FC: 22
CC: 1
CYA: 45 -50 (seems to have dropped a bit from the backwashing + rain we have had.)
Try stopping the DE. I put DE in my sand filter and my pool went all white haze for a few days.
It has been about two days since the last time I added any cellulose/DE. I backwashed it out and stopped adding it because as Yeggim suggested, it didn't seem to be helping.
Something has changed though, After two days of no real pressure changes and not having to backwash, the filter pressure spiked last night and since I backwashed it this morning has been rising about half a pound per hour over the past two hours.
Hopefully it is a sign that some of the particles are starting to get caught and filtered out now.
- May 22, 2013
- 2,796
- Pool Size
- 12000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
My understanding is they aren't using DE, they are using a Cellulose filter aid. Something like this: http://www.lesliespool.com/leslies-cellulose-fiber-bag-for-de-filters-3-lbs/cellulose-fiber.htm
Was the DE you used pool grade (heat treated) or possibly a garden or pest control grade ?? There is a difference and maybe that is the reason you had a bad experience with it and it went through your filter ??
Day 13
Still headed in the right direction but the improvement to overall clarity is so slight that without the daily comparison photos I would be hard pressed to notice the change.
Overnight FC drop was minimal 1-2ppm so not too much left in there to kill. Right now I just need the water to clear up so we can find/remove any last hidden bits of crud and move to the final stage of the SLAM.
Still headed in the right direction but the improvement to overall clarity is so slight that without the daily comparison photos I would be hard pressed to notice the change.
Overnight FC drop was minimal 1-2ppm so not too much left in there to kill. Right now I just need the water to clear up so we can find/remove any last hidden bits of crud and move to the final stage of the SLAM.
Day 14
Again.. Almost no overnight chlorine loss but still only the tiniest of improvements to clarity. Haven't had to backwash the filter for two days now so it would seem that whatever particles are left in the water are just too small for the filter to catch. The pump/filter has a total turnover rate of 3.2 hours so the water is definitely being processed several times each day.
Costs so far two weeks into this:
Bleach: $246
City Water: $193
Again.. Almost no overnight chlorine loss but still only the tiniest of improvements to clarity. Haven't had to backwash the filter for two days now so it would seem that whatever particles are left in the water are just too small for the filter to catch. The pump/filter has a total turnover rate of 3.2 hours so the water is definitely being processed several times each day.
Costs so far two weeks into this:
Bleach: $246
City Water: $193
If you are stuck, then there are some last-resort methods in case the particles you are now trying to filter are to fine for the filter to catch.