reflections on diy trickle filter

[justDIY]

There are a lot of plans for building trickle filters on the net, so, not being one to follow, I had to take a few ideas from others and then re-invent the wheel anyway!

I liked the 5 gal bucket trickle filter, as it seems very compact, while still providing a very large bio-media capacity.

This plan however, had some bugs, namely a self-rotating spray bar that trickled water over the bio-media.

I don�t know how it�s working for the author, but I couldn�t see it lasting very long after a good sludge of bacteria and algae grew inside of it.

Other �bio-tower� designed call for a �drip-plate�, in which dozens of tiny holes are drilled allowing for water to trickle over the bio-media. This idea probably works well, but those tiny holes will gloss over with sludge too, and the plate requires too much room, imho for a compact filter.

My solution was to build a circular spray loop, center fed via two paths. I constructed the loop from 8x �� cpvc 45� elbows and 3x �� cpvc tee�s, connected together with short pieces of �� cpvc pipe (cpvc is the yellow stuff, genova I think). Water enters the first tee through the lid of the filter, where a valve connects it with the overflow (see my diy overflow post). This tee feeds two more tees connected via short pieces of pipe. These tees are then joined into a ring constructed of the eight elbows and more short pieces of pipe. Holes are drilled in all of the pipe pieces, using a 1/8� drill bit.

I didn�t weld any of this together, so I can pop it apart every few months and run a bottle brush through to clear the sludge.

(insert ascii art diagram here � pff, octagon�s are too hard to draw with ascii (anyone want to take a stab?))

This loop sprays �dirty� water onto about a 2� mat of filter floss (additional pre-filter), which covers about 20 plastic scouring pads (the roundish woven plastic kind). The pads should provide ample bio-area, and they�re all I had available (out of 5 local gun shops, no-one had shot-gun wadding!) At $0.45 for 3, they�re pretty darned cheap! These pads sit on-top of a plastic colander which was trimmed and inverted, wedged into the bottom of the bucket. Under the colander there is about 3� deep by 12� round free space as a �sump� that contains a MaxiJet 1000 pump, which returns water to the aquarium via a �� bulkhead in the side of the bucket. There is probably room for a pair of 50 watt submersible heaters, or a co2 diffuser, but I don�t know about putting hot things in a plastic bucket, and adding co2 to a biological filter might be counter productive as far as the aerobic bacteria are concerned.

The hardest parts of this project were building the spray-loop and finding suitable bio-media. Now that I�ve gotten my overflow working correctly, this filter should provide PLENTY of bio-filtration for my 30 gallon tank (maybe 45 gal soon), snatching up any bio matter that the plants didn�t grab first.

I may build another one to filter a 90 gallon pond (in ground), but instead of gravity feed in, pump out, I�ll make it pump in, gravity feed out. It should keep the goldfish happy.

Ttyl
Gordon

[reefrunner69]

Looks great!! Would like to see some pics of the filkter and the overflow. Approximately how much did it cost for you to build this filter?

[justDIY]

quick run-down of the parts list refreshes my memory....

*sump parts
1x 5 gallon "Homer" bucket with lid ........ $4

1x 4 quart plastic colendar ........ $1

*spray bar parts
8x 45° 1/2 inch cpvc elbows ....... $2.32

3x 1/2 inch cpvc tee's ........ $1.65

1x 1/2 inch cpvc to FPT ....... $1.09

*bulkhead parts
2x 1/2 inch barb to 1/2 MPT fittings ....... $2.20

2x 1/2 inch rubber o-ring ....... $1.10

*filter media
20x (roughly) plastic srubbers ....... $6

*misc parts
1x MaxiJet 1000 powerhead pump ~250gph ........ $free with used tank I bought

2x 1/2 inch sch 40 FPT ball valves ....... $9

10 ft 1/2 cpvc genova pipe ....... $1.49


So, roughly $30 for the setup .... 1/3rd of the cost is for some expensive threaded pvc valves, which you may or may not really need but I like having that additional level of disassembly available that threaded parts afford ... if I would have used weld-on valves, that would have costs 1/2 as much

Seeing as how this filter easily has 4x the media capacity of most any canister filter (costing anywhere between $100 and $300) [fluidized beds aside], I'd say it's a pretty good bargain. Besides, fluidized beds seem to be persnickity about getting jammed up or stalled.

Of course, it doesn't have fancy trays or a valve shutoff interlock system, but it does provide the increased efficency of a true wet/dry medium, instead of a totally immersed medium that most canisters provide. Depending on the powerhead / pump used, it is also self priming (my maxijet is self priming when used as a pump), which means quick and automatic recovery after maintence or power outage... most canister filters have at least some trouble with this.

The capacity of the bucket design (thanks to whoever thought it up!) is limited (within reason) only by the flow-rate of the return pump and overflow feed and it's relationship to the aquarium size. I guess if you had a truely enormous aquarium, it's bioload would be too much for something like this to handle, but those big aquariums need swimming pool capacity filters anyway. I guess you could build a similar filter using a 50 gallon poly barrel or 100 gallon rain-tank ... lol!

[Electrobes]

have any pics of this construction? I hate being a visual learner

Most of the LFS's around here do similar things with 5 gal buckets...One in particular uses small chunks of pourous rock for the media and then it drains into a Rubbermaid tub. Then back to the tanks...Bigger setup than you are talking about but still very much effective in filtering...Kudos to you

[justDIY]

sorry electrobes, no pictures as of yet... the only digital camera I have is a webcam, and computer room is a ways from the fish tanks

Probably the weekend after next I will be building my new PC's a hood for the 30 gal, which still has some lingering goldfish that haven't made it to the pond yet

I'll be taking analog pictures then, so maybe I'll snap a few of various DIY'd projects as well.

[justDIY]

Trickle filter pictures

Only things not pictured are is the colendar that separated the biomedia from the pump and the pump itself sitting inside the filter.

This filter is offline right now because I don't have a slow enough pump for it... in other words, there are some flow restiction issues that need to be worked out!

EDIT 10/2/2003 See some pics of the trickle filter on my gallery:

http://www.myaquaria.com/gallery/diytf10

This is the sump the overflow is currently supplying water to. The multi-colored orbs are plastic scrubber pads. In the back left, you can see the mechanical filter, which is a plastic juice bottle stuffed with filter floss, the outlet from the overflow dumps into this. I also have some bags of carbon laying in there. The pump (under the orbs) is a maxijet 1000.

[mono]

So you have one pump in the sump, and another in the filter?

Water will overflow into the bucket, then pumped out of the bucket into the sump, then pumped out of the sump back into tank?

sorry, just trying to conceptualise...

[justDIY]

Originally Posted by mono

So you have one pump in the sump, and another in the filter?

no, the picture of the sump is just to show the biomedia I used in the filter. The filter isn't being used right now because I don't have any pumps slow enough to run the filter properly. Instead, I am just running the sump alone as a filter.

I have to take a drill to the spray ring and enlarge the holes - that should increase the flow rate, so the pump I have will work.

Originally Posted by justDIY

This filter is offline right now because I don't have a slow enough pump for it... in other words, there are some flow restiction issues that need to be worked out!