fluidized bed filters

[kba981]

are they any good or not and why

[prodman]

Do you mean for running phosban or rowaphos? If so they can be very effective at lowering phosphates. Just be carefull not to lower it too fast because thats when problems seem to happen.
I was using like 1/4 cup of rowaphos changed monthly in my 65g tank to give you an idea of how conservitve it should be used imo.

[Reefvet]

Originally posted by kba981
are they any good or not and why

Fluidized be filters are good at producing nitrates, accumulating detritus and burning out pumps from the back pressure. Popular for swimming pools where you backwash them weekly to clean.

Fluidized reactors are an entirely different device, that's where you run carbon, rowaphos etc..

[Herbert T. Kornfeld]

"Fluidized be filters are good at producing nitrates, accumulating detritus and burning out pumps from the back pressure. Popular for swimming pools where you backwash them weekly to clean."

-Reefvet

I am not going to start anything here, I agree with almost everything said here, but I do want to point out that while fluidized bed filters are made to outperform larger wet-dry filters in the aerobic bateria category, and my FB300 makes a wonderful phosban reactor, they do not accumulate detritus...their fluidized media column prevents buildup and clogs...the tumbling media cleans itself with every time two grains collide.

I just want to point this out because it is also one of the main reasons why they make great carbon / phosban reactors...they dont clog and provide great flow distribution across the media.

And I have never had one cause enough back-pressure to blow out a pump. I have been running one for almost a decade now on a MJ600...never a problem.

[Reefvet]

It sounds to me like you're referring to a fluidized reactor, it wouldn't be much of a filter if you can run it with an MJ600.

About a decade ago fluidized bed filters became the craze, you never hear of them today, they were much larger than what is commonly used for rowaphos/carbon etc. today.

[chtan]

"Fluidized be filters are good at producing nitrates, accumulating detritus and burning out pumps from the back pressure. Popular for swimming pools where you backwash them weekly to clean."

Reefvet, I think u are referring to sand filters ... fluidized bed do not need to be back washed.

[Ah64av8tor]

FB filters are very efficient and hence produce nitrate as designed.
I believe the reason they aren’t popular is that not many people know how to use them properly or understand them; they are not Plug and Play!

I never understood how complicated they were until I started volunteering at Mote labs, we use a lot of FB filters there with only annual cleaning and they never clog. The hard thing about FB filters is you must have the right amount of media and proper amount of flow to process the NH3 efficiently other wise you can starve the bacteria, or not have enough surface area / bacteria to reduce all of the NH3.

You have to adjust the amount of media to accommodate the most efficient amount of bacteria to convert all the NH3, and keep the flow slow enough to allow sufficient contact time. A three inch column of sand 10 tall expanded to 12-13 inches (15 -30%) with about 50 gph flow this will process 50 grams of food / waste a day. (I don’t come close to 50 grams on a heavy stocked 150.)
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I am planning on installing one in line going to my fuge to aid in growth of macro.

[Herbert T. Kornfeld]

The rainbow lifeguard FB300, 600, and 900 are fluidized silica sand filters. The model numbers are also the gallons that they can process...and they are pretty small. The 300 and 900 are what I have...I use the 300 as a carbon/phos chamber, and the 900 as a aerobic filter on the 360g planted tank. The 300 only needs about 150gph running through it to suspend the media...supposedly with enough filter area to equal many cubic feet if it were a wet-dry...while being only 2x to 3x larger than the current phosban reactors. I wouldnt use one on a reef however (at least with the standard silica sand media)...its for converting nitrate and ammonia to nitrate...dont want that really.

[Ah64av8tor]

The flow rate through your FB should be between 15 -30 gpm/sq ft of filter area so 150gph would be right at 30 gpm/sq foot with a 4inch column. 150gph would be to much flow with a 3 inch column.

The desired tank turn over through the FB should be at least 1/2 half of the total tank volume per hour, that would be where 300 gal would come from.

Now that you know the size and flow you can handel you can further dial it in if you know how much you feed.
Grams of food X 30 % = Grams of waist (NH3) aprox
Each gram NH3 requires 0.7 to 1 Sq Meter of media for mineralization. (1 Sq Meter = 1555 sq in)