DE powder making water cloudy

[gordyjamz]

Been trying the DE trick in the sand filter on and off so far this season and i can affirm that its making my water cloudy. anybody else see this happen? My filter is a older one, maybe the trick only works with newer ones. Theres nothing wrong with the filter, I just wanted to see if what everyone is saying was true so back in May I tried the trick. Water was cloudy back then(due to an algae prob and levels being off) before I did it, so I couldn't be sure if the DE was further contributing or not. So after getting all the levels straight (alk was high, had to drain to lower cya) and algae gone, I no longer needed to use the DE since my water was crystal clear. This week, I noticed a problem with some fine particles in the water. You could only see them while underwater with goggles on. Looks to be very tiny pieces of leaves or something. We do have a neighbors tree that overhangs the pool and loses its leaves, because I think its dying from a disease or something. Thats whole other story. Anyways, I tried the DE trick again, and woke up Thursday to cloudy water. My levels are fine. FC has never changed, I keep it 5ppm, because my cya is 60. CC is 0. Use the BBB method as well, not since May have I used pucks or powder, just bleach. PH is 7.2, Alk at 110. Don't know the hardness, because 1, the HTH test kit that I use doesn't turn red when adding the indicator, rendering me an inaccurate test, 2, I have a vinyl liner, so it shouldn't matter, and 3, I have no signs of high CAL such as crystal buildup or anything. So like I said, I've eliminated all other causes of the cloudiness, except the DE. And since that the only thing that has changed this week, it can be the ony possible cause. Anyone else see this happen?

[matt4x4]

Since DE does not make my water cloudy, and i don't think Poconos' gets cloudy, I would have to think that there is a problem inside your filter, possibly you sand has become veined and the DE is shooting through the sand, or it could also be a bad spider gasket seeing that it's an older filter.
Only an inspection of components would tell for sure.

[gordyjamz]

backwashed de powder out about 4 days ago, water is now crystal clear. The facts speak for themselves. DE powder can possibly make your water cloudy with older sand filters.

[KurtV]

Gordy, As Matt said, the DE is probably only making your water cloudy if your sand filter is letting it through to the pool because the sand is channeled or the filter is otherwise malfunctioning.

It seems unlikely that you'll be convinced otherwise, but I don't think the DE is making your water cloudy if your filter is functioning properly. It may, however, be revealing a problem with your filter.

Cheers.

[sevver]

The filter is old? Maybe the sand is hard and there are channels in it. I would tend to think that the sand needs to be replaced.

[duraleigh]

Gordy, my logic tells me you might be right......other's experience seems to indicate we're both wrong. Anyway, here's my thought:

Sand supposedly filters down to 60 microns meaning anything smaller can get thru.

DE supposedly filters down to 2 microns...that would make me think that DE granules are smaller than 60 microns. If they weren't, I don't see how they could capture 2 micron particles.

So, if that thinking is correct, some could work there way thru the sand...particularly if there was not enough sand in the filter or possibly if the filter was pretty small.

So, if DE particles are smaller than 60 microns, Gordy and I might have a point. How big are they, DE folks?

[matt4x4]

So we move on to the BIG question...... If the DE is making the water cloudy (meaning it is pushing through the filter and into the pool, I really want to know how your filter was THEN able to catch that DE (the same DE that is just washing through the filter making your water cloudy) in order for you to backwash it out (the DE that's just circulating with your water)?
Dead Algae particles are smaller than DE, how come your filter can catch these???? With DE added, you increase your filtering efficiency and now catch more of the dead algae particles per volume of water filtered.

Maybe it is a small filter, maybe the sand is low, maybe the sand is veined - any which way, I would open the filter and do an inspection, if the DE can wash through, so can dead algae since it's even finer that DE.

Diatomaceous Earth has a unique combination of physical properties:

High Porosity: Up to eighty-five percent of the volume of Diatomaceous Earth is made up of tiny interconnected pores and voids. It is made up of more air than diatom.

High Absorption: Diatomaceous Earth can generally absorb up to 1 times, its own weight in liquid and still exhibit the properties of dry powder.

Particle Structure/High Surface Area: Diatom particles are characterized by their very irregular shapes, generally spiny structures and pitted surface area. They average 5 to 20 microns in diameter, yet have a surface area several times greater than any other mineral with the same particle size. Diatomaceous Earth increases bulk without adding very much weight.

It is the irregular shape of DE that allows it to cling to the sand - almost like reaching out and grabbing it. Effectively, the DE will grab the sand as it moves through, and get stuck within the first inch or so of sand, clogging the spaces between the sand particles - just like the dirt would.