Fluidized bed filters

[salisbury a d]

What is a Fluidized Bed filter?
Life Gard has one.
My lfs is selling one for 59$.
Is it a good deal?
What do they do?
Will it help with some problems like hair algae and film algae?
Adam

 

[sonny]

A fluidized bed filter is a sand filter that uses a small powerhead to agitate sand into a cloud in a tube. The sand is then a home to millions of bacteria. It is similar to a trickle filter, but it doesn't have air in it. The benefit of them is they are very small for the filter capacity they have. I have used one on a large fish only tank with good results. That is a good price for the filter at a LFS. I paid that from a mail-order place. I don't recommend them in reef applications, as they will become nitrate factories very soon. They will encourage algae growth, not stop it!
Sonny

 

[salisbury a d]

I just found the filter in a catalog.
It said its job is to reduce ammonia and nitrates.
**If it reduces nitrates then why can it become a nitrate factory?
Adam

 

[sonny]

I'm sure it said ammonia and NITRITES. Big difference. It is a biological filter, serving the same purpose as a wet-dry filter. The cycle is ammonia to nitrite to nitrate to nitrogen gas. (hopefully!)
I don't think wet-dry filters should be used on a reef tank either. Neither type of filter contains an anoxic area (low oxygen) to reduce nitrates to nitrogen gas. You will need a deep sand bed with a plenum to do that efficiently.
Sonny

 

[reefj13]

I'd have to agree with Sonny, in a reef tank only true natural denitrification should take place.
Since wet/dries and sand filters are well oxygenated the anareorbic bacteria that break nitrate into nitrogen cannot live there. This type of bacteria only live in the center of lr and at the bottom of lsb's.
These filters also breakdown these waste products at alarming speeds(good for a fo tank) leaving no ammonia left for the corals!!!!! Corals need nitrogen like all living things and their favorite way to get it is in ammonia. Don't go home and piss in your reef tank though because corals only need very small quanities of it and localized fish waste is more than enough.