Can't get rid of fine sediment after using hth DE Filter Aid

[blairsooley]

I have been recovering my pool from Harvey. During the process, I had to do several backwashes and eventually decided it was better to clean and recharge the filter. I have previously used the DE from Leslie's without any issue. However, since I was at Home Depot I decided to try hth DE Filter Aid and had ready that the handy 6lb bags are great for my filter size. After introducing the hth, I noticed that my jets started to shoot cloudy water back into the pool. The water now seems clear when the cleaner is not running and I'm not brushing but there is a fine grey sediment over every flat surface and the cleaner stirs it up and turns the entire pool cloudy every time.

Anyone have this same issue with hth DE Filter Aid? Is it too fine for a Pentair DE filter?

 

[JoyfulNoise]

Welp, here are the ingredients -

Active ingredient- citric acid & butoxyethanol

Inert ingredients - Shell Flour, 84% Silicon Dioxide, fresh water type.

Couple of problems with this stuff. First off, the butoxyethanol is a surfactant, so think of it like a detergent. It is going to make most of the gunk captured on the surface of the DE MORE SOLUBLE in water and thereby help it to disperse better which means it's more likely to let the gunk pass through the filter rather than adhere to it. The citric acid will act as a mild reducing agent which will cause any trapped metals to redissolve into the water.

But what I don't get is the Shell Flour. You see, there are two kinds of DE - calcined (heat used to convert the amorphous silica into crystalline form) and uncalcined (amorphous silica). Raw DE that is not calcined is suitable as a food additive and acts as an anti-caking agent. It will also totally foul pool water as it will not coat the DE grids. This is also sometimes referred to as....Shell Flour.

Calcined DE, also known as pool-grade DE is what you want to add to a DE filter. It actually sticks to the grids and filters the water.

So, I'm not sure why they sell this stuff as an additive to a DE filter because i can not think of a more detrimental thing to do to a DE filter

Your only fix is this - tear apart your DE filter and completely clean it out of everything that's in it and on the grids. You may need to soak the grid in a mild cleaning detergent or trisodium phosphate to get the "filter aid" to release. Then you want to reassemble the filter and recharge it with ONLY POOL GRADE DE. After the filter is recharged, then use a manual vacuum to slowly vacuum up all that "filter aid" off your pool floor. After it is all gone I would suggest your tear down your filter again and clean it all out. Backwashing will not do, you must completely clean the filter.

Sorry, but this is why TFP teaches pool owners to be very wary of these "magic potion" products....most of the time the are complete junk and, for some reason, these companies can't seem to hire any chemists that actually know what the heck they are doing....

 

[blairsooley]

Thanks JoyfulNoise. Its the only product I was able to find outside of Leslie's and there was nothing to suggest it was special in any way or unlike any other DE. A couple of DE filter cleanings is no big deal. I haven't had it completely apart anyway so it'll be a good time to inspect the grids for tears.

After bringing the pool back following Harvey last week, nothing else is daunting.

 

[JoyfulNoise]

Thanks JoyfulNoise. Its the only product I was able to find outside of Leslie's and there was nothing to suggest it was special in any way or unlike any other DE. A couple of DE filter cleanings is no big deal. I haven't had it completely apart anyway so it'll be a good time to inspect the grids for tears.

After bringing the pool back following Harvey last week, nothing else is daunting.

Good luck.

There are only three things that can be used in a DE filter - pool-grade DE, pearlite, or cellulose fiber. Nothing else will do.