This is my DE filter setup. It is a Hayward EC40 DE pool filter. It has 25x the surface area of the Diatom XL I linked you to earlier. It requires an external pump. The pump I am using is 1/8th hp. I have run it for 9 months straight with the only maintence being turning off the pump and pumping the handle on the filter up and down a few times once a month. With the surface area and the way the filter recycles the media I don't know when I will ever have to actually change the DE.
A friend gave me a Diatom D-1 (Smaller than the XL) about a year ago. I let is sit around for a while and didn't bother messing with it. One cloudy tank day I figured what the heck. The first time getting it up and going was a royal pain. But after messing with it I got it primed filled and running. 10 minutes later... perfectly clear water in my 110g. I mean PERFECTLY CLEAR!!!! Like nothing I have ever seen in my tank before! So I would pull it out every other week to clear the tank up after a water change and got to the point that I could setup the Diatom in just 2 to 3 minutes. (The stock hoses are a pain to use. I changed mine to black spiral pond tubing).
You really only need to run the Diatom XL for an hour or two at most. I would leave mine running for a few days until the flow would start to slow down.
It is about the same noise level as my Magnum 350 which also isn't a quiet filter. It is a bit more hassle than an ordinary filter. It is unquestionably worth the hassle!!!
My 110g sits in a window with direct sunlight. I was able to remove the background from the tank and not have any algae problems since I went to the Hayward DE filter. I believe the DE removes the free floating algae from the water before it can settle and colonize. (I also use Pothos hanging over the rim of my tank which might be out competing the algae for nitrogen compounds) The marketing literature says DE will remove Ick fungus from the water. I believe this claim!
There are a gazillion fine pores in the DE powder which perform the super small particle filtering (Down to 1 micron is what I believe the literature says). I don't know if Nitrifying bacteria like DE but is sure seems like the DE would provide more surface area than any other media available for beneficial bacteria to colonize.
The DE filter does not max out at 8 hours because of heat. It is very possible that a really dirty tank will plug all the DE pores in 8 hours and it will slow to a trickle. For me I would get a few days before this happened in my dirty 110g.
It isn't loosing prime that they are referring too. What they are referring to is the DE powder falling off of the filter screen when there is no flow through the filter. I had no problem stopping and restarting my Diatom D-1. When I would restart it the filter would put out a small cloud of DE in the tank. The filter itself would clear up this cloud in 10 minutes or so. But the directions say not to stop and restart the filter because the DE will fall off the filter screen.
The Diatom DE filters are closed loop design that will not loose prime if you don't take the hoses out of your tank... just like any other closed loop canister filter.
On the Hayward stopping the flow through the filter and knocking off the DE from the filter screens IS the recommended maintence routine. I initially charged my Hayward with about 5 cups of DE powder. When I opened the filter this covered all the filter tubes/fingers (screens) with a good 1/4" + of powder. You knock all of the powder off the tubes and let it recoat the tubes to expose a new layer of DE to the surface and make a fresh layer of DE pores to trap particles. I thought this knocking off and recoating was kind of dubious when I bought the filter but it does work extremely well exactly like the manufacture says it does.
By the way, if you do a little googling you will see that DE is used a lot in food processing. Filtering wine to make it clear, not cloudy is a very common application for DE filters.
