Backyard Aquaponics
A place to discuss aquaponics

The mechanics of the Drum filters aren't all that difficult to understand but it would take time to get it right. Here's a few pics of the internals on a small commercial unit - http://koi2day.com/forum/index.php?topic=4367.45

It's very do-able but there are other ways to setup a screen filter which should work for a system this size and don't require the purchase of, or building of, a drum filter - This was a pretty good system I thought https://www.youtube.com/watch?v=Ul_oPDh0gh4

He also has an update on an important change he had to make to the screen, so be sure to check that out. I watched a part of the video and it sounded like a problem with corrosion of the screen and toxicity because of using the wrong material but I'm not sure. Anyway this would work with the right material.

I'm not sure but I think he used filter socks as well, which I think is a bad idea because they'll clog fairly rapidly. I'd be looking to see how the drum filters handled the waste after it's removed from the drum by the spray bar.

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This is an interesting read on solids removal - https://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/5%20Solids%20Capture/Solids%20Control.pdf

I'm not sure where the static K2 filter fits into that scheme

Great, thanks for the links scotty. I have been following robs and cc bears builds. Fish and worms on YouTube has some really info regarding RAS as well. Are you doing anything different to your RAS to help prevent the ammonia spike everyone seems to get?

I've only had one ammonia spike which was from letting the filter run too long and after flushing out both filters that cleared in a day or two - no losses partly because the current conditions mean the ammonia is less toxic. I wasn't seeing any problem and thought everything was going well so I didn't clean the filter as often as I should have. It turned out I was getting lots of solids accumulating in the MBBR and after several weeks I believe it caused the ammonia spike. No fish losses because conditions favored the ammonia not being toxic. Finding the solids accumulating so well in the MBBR is what made me look into static filtration with Kaldnes media.

Thanks for reminding me about FishandWorms system - I liked his old system but I hadn't seen his new system - Wow! I wonder how long the screens on the drum filters are going to last, he's running a light load and those are still being cleaned pretty often. Here's the link to what I was watching - https://www.youtube.com/watch?v=fcW78U4DRoY

For a single IBC RAS system, I think the drum filters only make sense if you have lots of money - not that I wouldn't like one .

Hi Scotty how often are you cleaning your filter and what is your average Ammonia reading between flushes. Cheers

Roughly every two weeks at the moment Bear. Average reading is roughly 0.7 mg/l, temp is around 50 F and pH is 6.5 but has been falling consistently since September when it was above 8.

I was flushing every 2 or 3 weeks before I got into trouble when I let the filter go about a month without cleaning. I noticed the fish weren't eating so I checked the system and found the ammonia at 1.0 mg/l. I completely stopped feeding and it still climbed until it hit 2 mg/l, 2 days later. At this point I flushed both filters a couple of times and it has continued dropping from 1 ever since. It's currently 0.25 mg/L. I don't know if it ever hit zero but it's common to have a trace reading for either system this time of year.

FYI -
Nitrites were also a problem when the ammonia spiked.

I have some Phosphates - the reading is below 1 mg/L but appears to be rising. I think this may indicate it's time to flush again, since it was at 1 when I found the first ammonia reading and fell to zero after flushing the filters. The waste is breaking down and releasing phosphate other than that I can't be sure what it's telling me or if this will happen every time. Phosphate accumulating organisms may not be present in high enough numbers to take in the phosphate so this may disappear as their numbers increase.

I got a strange reading of 52 for the Nitrates that was probably bogus because it reads zero normally. This happened at the end of January when the ammonia hit 0.5 (down from 1.0 on the previous reading).

Scotty

I would imagine static filtration is the same as bead filtration. Water passes up through the media (usually with a media of under 1 sg) there are a number of reasons as to why it captures particles of varying sizes. Cleaning requires turning the filter off and moving the bed usually mechanically this dislodges the crap which can be drawn off. Basically similar to a pool sand filter except you have floating media.

That's what I thought as well Sleepe. I hesitated to say it though because many bead filters appear to be totally enclosed so I thought they might be operating under pressure or vacuum at some point . Thanks for the feedback.

Dont know if you have read this one but here's another article on solids removal using (in order from most solids removed to least) drum v radial v swirl.

http://integrated-aqua.com/wordpress/wp ... epaper.pdf

Thanks FishNChips, that's a good paper and a big part of why many here (including me) went with RFF's as opposed to Swirl filters. Always find something I missed when I look back through articles like this, I had forgotten about the Drum Filter comments.

While pool sand filters work under some pressure, and a pressure gauge is incorporated to let you know when they need backflushing I think the main reason for containment in a bead filter is to avoid them overflowing the top.
This thread shows Frank's bead filter ie upflow static bed filter. viewtopic.php?f=8&t=4213&p=151277&hilit=bead#p151277

Hmm, don't remember having seen that before. The screened pipe as the outflow is a good way to do it. I wonder if he got the peristaltic pump to work?

I've got to add aeration, fix the drain in the 55 gallon and put a ball valve on the drain from the 15 gallon barrel, add a bit of support underneath and maybe a couple other bits then I'll be able to test my filter out. Here's a pic of where I'm at so far -



inflow on the left outflow on the right - static media in the blue buckets. Moving bed media in the outer area. The 15 gallon barrel is not quite as high as I would like and I plan on putting a lid on the bucket. I'll probably T off the outflow for a bypass from the 15 gallon drum but it's kind of tight there.

Cheers

Be interested to see how it goes scotty.

Just be a little careful of how it can escape, I have had bottlecaps and bioballs manage to sneak out of a filter and the small stuff is a pita.

Not sure how Frank went with the peristaltic pump but they are simple to make self priming and have no problems with semi solids.

Scotty/Sleepe (or anyone for that matter), have you guys had experience with bead filters? AKA “expandable granular biofilters” or EGB’s?

Been reading up on them the last couple of months and a BBF-XS2000 popped up for sale in my area just recently. From my understanding they are the solution to overcome the problems associated with sand filters in aquaculture. Compared to sand filters, bead filters are immune to biofouling, never require replacement of the bead media, minimise water usage and reduce energy cost by lowering pump head requirements.

In their raw state they seem like a MBBR but its their design that confuses me. Ive read that in addition to mechanical/biological filtration thy also provide clarifying by means of removing suspended solids by at least four different mechanisms as water is passed through the packed bed of plastic beads. Particles >100 microns are subjected to physical straining. For slightly smaller particles (50-100 microns) the most dominant mechanism is settling. Suspended particles (5-50 microns) are removed by interception, a subtle process caused by collisions between the particle and the bead media surface. Finer particles (<20 microns) are removed through bioabsorption, the capture of particles by the bacterial biofilm. Bead filters are excellent clarification units, capable of maintaining display quality water at high waste loading rates. Studies have shown that Bead Filters capture 100% of particles > 50 microns and 48% of particles in the 5-10 micron range per pass.

Apparently also can be automated?

Any pro's or con's?

Just found this

https://freshbydesign.com.au/sites/fres ... deshow.pdf

I've read a little bit about them Charlie. I think Ebeling has been involve in quite a bit of research with these and has lots of little tidbits out on the Internet -

http://aalso.dreamhosters.com/oldsite/2009presentations/EbelingImprovedSolidsRemoval.pdf
There's some information in his reviews that are posted online as well

https://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/5%20Solids%20Capture/Solids%20Control.pdf.

http://integrated-aqua.com/wordpress/wp-content/uploads/2011/06/Holder-Timmons-Paper-Dec-6-2005.pdf

He mentions 5 to 6 lbs of feed per cubic ft of media in this paper - https://ag.arizona.edu/ceac/sites/ag.arizona.edu.ceac/files/16%20Ebeling%20Aquaponics.pdf

http://ag.arizona.edu/azaqua/ista/ISTA7 ... erview.pdf

I think I've seen this used by a few Koi enthusiasts - http://www.aquasonic.com.au/product/polygeyser-pressure-model-3ft3/

They seem like they would be a good route to go filtration wise but many of these are pressurized if I recall correctly. I went with packed media for now combined with MBBR. I think micro bead filters like these would do the same functions better, they have more surface area and because the beads are smaller will do a better job filtering small solids.

Don't know if these would be food grade which is what I think they use but maybe
http://www.beanbagbeads.com/polystyrene_beads.php