Gravity fed fluidized filter

[Ichthius]

I built this today out of some scraps. It is gravity fed from a catfish tank through a one inch pipe from the tank overflow. There's about 400 gph flowing through it.

http://goldfishgarage.blogspot.com/2010/03/gravity-fed-fluidized-bed.html

[BruceP]

Nice job David:worship:

[Ichthius]

Here’s an Update with the stack vented to remove bubbles and with the sharp sand replaced by glass beads:
http://goldfishgarage.blogspot.com/2010/03/gravity-fed-fluidized-bed-biofilter.html

The beads were brand new and took a bit of effort to wet them. The stuck to any bubble that made it down the probe. Running them through a net seemed to get them all wetted. A little soap and a pan would have made the wetting process better but these catfish are making more waste than the bioballs can handle.

[Corrie]

David, I tell you, I worry about those things. You probably have more reliable power than we do. Our power goes on and off too much here for those.

[Ichthius]

Don't worry, just don't use one.

Mine restart just fine after a power outage.

My four filters at work have 10 tons of sand in each of them and they start back up just fine.

[bekko]

Fluidized beds have a small footprint relative to their nitrification capacity. But, that works against you when the flow stops because the oxygen is rapidly depleted and the nitrifying bacteria will be dead in less than an hour. Open media have more more interstitial water and more leeway when the power goes out.

-steve

[Ichthius]

That is true if the filters are over run with heterotrophic bacteria. If maintained in the appropriate way with only thin film autotrophs the beds can settle and start back up again without missing a beat. It also helps to not enclose the filter like the rainbow lifegaurd unit and to purge the first fee minutes of flow after start up.

I have four at work that are huge and the longest shut down I've had was 6 hours and I never detected ammonia after start up.

Run the fast and open and the is not a filter that can compete inters of efficiency small foot print lack of maintenance cost and ability to rapidly adjust to changing bioloads.

[Ichthius]

Here (http://goldfishgarage.blogspot.com/2010/04/200-gallons-per-minute-fluidized-sand.html) is one of 4 large fluidized sand biofilter that I have at work. They have 10 tons of sand per reactor for a surface are of 81 acres
and are capable of digesting 100 pounds of food per day. They have ultra fine sand for total biofiltration in a single pass. We could
enlarge the sand to significantly increase the flow rate. Current models are getting 150 gpm out of a 42 inch reactor. They have very fine sand which is the most difficult to refluidize after a power outage but with proper design the refluidize on their own.

http://goldfishgarage.blogspot.com/2010/04/200-gallons-per-minute-fluidized-sand.html

[Ichthius]

The gravity fed glass bead fluidized bed biofilter was inoculated with 500 mls of biologically active fine grain quartz sand. The 300 gallon monster fish system was running at 1 ppm ammonia. With in minutes of inoculation the effluent of the sand filter was at 0 ppm. Within two hours the ammonia was non-detectable.

The fine grain quarts segregates to the top of the glass beads. The sand can been seen as a one inch band of tan across the top of the blue glass beads.

Photos and video are here:
http://goldfishgarage.blogspot.com/2010/04/power-of-fluidized-sand.html