DIY Fluidized Bed Filter Media?

cathos

Feeder Fish
MFK Member
Mar 10, 2011
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Denver, CO
You can use large particle sand, biopellets (these are usually slowly consumed by the bacteria), low density plastic rings (this includes kaldness K1 and K3 and any of the varieties that look like slices of shotgun shells), and many other things.

The larger or lighter the particle, the easier it is to screen the outflow. However, using sand as a fluidized bed provides a ridiculous amount of surface area. Sand needs a large flow rate to keep fluidized, however, and may be difficult to restart after a power outage.

Most waste water treatment facilities in the U.S. use either sand or the kaldness-type media.

Biopellets are very popular with saltwater aquariums and ray tanks because they keep a much larger amount of bacteria readily available for use if the amount of waste changes because they provide nutrients for the bacteria.
 

JK47

Retired MFK Admin
MFK Member
Aug 4, 2008
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I tried:
Eheim substrat PRO = no (too heavy, would not fluidize)
PFS = no (too heavy, would not fluidize)
Stock sand = no (when pump turned off, it would back syphon and clog)
I settled in a finer grade sand (quickrete media sand) brown bag, green label at home depot. 100 lbs for $6.99 ;) if the flow rate was higher going through my system, this may not be an option but it works for lower slow setups perfectly and has never clogged when pump is off.
 

Wiggles92

Dovii
MFK Member
Apr 25, 2009
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Thanks for the help, everyone!

It seems that my options are Kaldnes K1/K3, sand, or bio-pellets. I'm probably going to end up going with sand because this is going to be a pretty big fluidized bed (estimated to be at least 30 gallons), and the sand will give good results while keeping the cost down. By the way, I'm going to be converting a 55 gallon plastic drum to a filter with a fluidized bed for my pond; I'll make a thread with the design and build walk-through when I start working on it.
 

vamptrev

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MFK Member
Apr 23, 2007
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there are better types of media then k1

do a search on ultra 2, has alot more surface area
 

Cablemonkey

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MFK Member
May 10, 2011
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Everton, MO
Aqua Ultraviolet Ultima II Filter Media was the only one I could find.
 

sam8fish

Feeder Fish
MFK Member
Feb 9, 2012
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Minnesota
everyone I have seen uses K1 but i found something that works just as well and is REALLY cheap, drinking straws cut into 1/2" pices
 
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Satanas90

Feeder Fish
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May 24, 2011
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Yuma
everyone I have seen uses K1 but i found something that works just as well and is REALLY cheap, drinking straws cut into 1/2" pices
Does starws really work??? I can get a hold of many straws.....hundreds.........I wanted to set up my sump...
 
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