Thomas and I have designed and built a working canister filter.

We used a gallon salad dressing container, the kind that almost every restaurant in the United States would have, as a prototype. It needs to be the type with a screw lid, not a pop-top.

Figure 1. Gallon Salad Dressing Container


We've also toyed with the idea of using an ice tea container.

Figure 2. Sun Tea Container


Thomas' plan is to eventually make a permanent one out of 6" PVC pipes, but we haven't made much progress on that one yet.
We've built it but no pictures quite yet. However, I have designed it on paper for the general idea.


Parts Needed:
- Water pump (we used a Rio 2100: 692 GPH)
- Canister (see above, or get creative)
- Tubing (we used 20' black vinyl tubing)
- Outlet tube/U-tube/Discharge pipe (see Fig. 3)
- Filter media (we are using a coarse filter pad, bioballs, and fine filter floss)

Figure 3. Outlet Tube


Tools:
-- Knife and/or drill to make holes in canister (we used a Leatherman multi-tool and carved the holes)
-- Aquarium sealant or superglue, whichever you prefer
-- Nylon tape (to help seal any threaded connections, including the lid)


You're also going to need to familiarize yourself with plumbing connection lingo.

Plumbing Fittings:
-- Nylon barb to MIP adapter; 3/4" x 3/4"
-- Nylon barb to MIP elbow; 3/4" x 3/4"
-- (2) Slip bushings; 1" x 3/4"


Basic Design:





A higher resolution photo can be found here.



Questions, comments, compliments and suggestions welcome!

Thomas should be posting actual photos of the setup once our powerhead arrives.

Wow. It looks like a great idea on paper. I want to see pics of the real thing!

Have you tested it yet? How much water pressure are you getting at the outlet? What size tank is it intended for?

And finally, good for you for designing a cheaper alternative. Being a poor college student is truly the mother of invention.

We tested it with a 170 GPH Penguin powerhead we had hanging around the house and it worked just fine. It leaked a little, but we're just going to seal it up with some aquarium sealant.

Haven't tested water pressure, but even with a 170 GPH it's enough to push the fish around. We're addressing this issue with a home-made spray bar. Pictures forthcoming.

It's intended for any size tank, really. You just need to choose a powerhead with the GPH that you want. I'm going to throw it on my 45gal container pond. I got such a powerful water pump because I want to be able to still use it as I upgrade to bigger tanks over time. Original plan was to put it on my 20gal with a flow control and diverter so that the fish aren't constantly caught in a VERY strong current.

The original design called for the use of threaded bushings used as nuts to press the threaded ends of the hose barbs against the container/lid, making a tight seal with the container (as in a bulkhead). However, I discovered that the Iron Pipe standard (MIP and FIP) uses tapered male threads, so that it is very difficult, if not impossible, to thread two pieces completely together. This insures a tight seal between a pipe (male: MIP) and the connector (female: FIP), but does not work for my purpose.

I'm sure there would have been an other way of using threaded fittings, but I already had the hose barb connectors, so I looked for a slip fitting that would work in place of the threaded bushings described in the diagram. I ended up using a PVC slip x slip connector (1" or 3/4"? I don't recall what size) that just fit over the threaded part of the hose barb conncectors: I wrapped the threads of the hose barb connectors with lots of nylon tape, added super glue, and pressed the slip connector firmly on (sandwiching the container wall in the middle) until the glue set.

The connection in the lid is sealed very well, but the one toward the bottom, with the 90º elbow, leaks a little bit (a very slow drip; the puddle doesn't even cover the bottom of a 5-gallon bucket). The bottom connection is in rather thin, flimsy plastic, just where the container starts to curve, and the hole was poorly-fitted. I will seal it later. Removing the lid to access the filter media is tricky: one must hold the filter above the tank to prevent draining the tank through the spectacular siphon action.

I was thinking about the syphon action when you wanted to service the canister. Would it be possible to put one or both ends of the hoses into a bucket below your jar to drain the jar only when you want to get into it? Does shutting off the pump close the connection at that end?

I don't have much experience with this, but reading about other people's ideas is fascinating. I'm going to try to build my own filter for my pond soon, and I'm learning a lot this post. Thanks for writing about it!

looks interesting.... it might be good for a backup for me.

Well, to be honest, we haven't quite worked that out yet. It's one of the items in the "possible pitfalls" at the bottom of the page. When we get it all set up with the pump and bioballs (which arrive next week), we will find a way to get into the jar without having catastrophic water spills.

For an outdoor pond, however... I don't think it really matters if you get water everywhere when you're servicing your filter?

Yeah, at least no one gets mad at you for spilling water on the ground outside!

My concept will be a little different in that I am converting a large planter/fountain into my filter. It will be skippy filter style, but with the water pumped into the bottom, hopefully go up through some filter media and spill over the top, then back down into the pond. I hope to do the plumbing this weekend, and will probably write it up in the pond section.

Powerheads don't stop the flow when they're off, so adding a ball valve to the hose that comes from the powerhead would be a good idea. Also, the return hose can be stopped from back-siphoning by using a check valve. However, these things cost more than I'm willing to spend right now.

you guys are my heros!! i'm going to start picking up supplies this week. YAY!!

Thanks, liz! that makes my day.

The current design is working pretty well. Its output is a home-made spray bar (a pipe with holes drilled down one side), and its on a 20 gallon tank. We're working on a second canister filter: This one will use 6" plastic pipe for the canister and be much more sturdy than the gallon dressing container. It will also use the new 692 GPH pump and be installed on Joy's 45 gallon pond (have you read that topic?).

Expect more pics and designs soon.

The pump and bioballs arrived today!!

mmm...a couple quick questions...

is there a difference in bioballs? im going to have to order those so i figured i should ask before i make a big purchase for the wrong kind or a bad kind.
as far as coarse filter pad...can you use those cheap 6pack plastic-ish scrubbers from w-mart or a dollar store or does it have to be something specific? here's a pic of what i mean --> scrubber
for filter floss, would quilt batting work? its 100% polyester too...

bear with me, i'm totally new at building anything like this...this is only the beginning of the tons of questions i'm sure i'll have!

Bioballs are pretty much bioballs. We ordered ours off BigAlsonline.com, because it's cheaper that way.

As for the coarse media, we didn't mean scouring pads. In our local LFSs you can buy "bulk" filter padding, something more like this.

For the filter floss, quilt batting is pretty much exactly the same as "filter floss." The difference? The label, and the price tag.

Keep them questions coming!!

*raises hand*

Do you think this would be possible to make on a smaller scale?

I'm completely DIY dumb. I wish I even was capable of building something neat like this.

Can't wait to see pictures of the finished product! It looks like you two have thought this through.

Wow, that's a hefty powerhead! I was under the impression that the large volume of filter media in a canister filter enables you to get by with less than the standard 10x gph, but I'm probably wrong about that. I would worry about it being very difficult to get leak-free seals on the canister with that volume of water being pumped through it that fast, but you guys seem to be pretty savvy about this DIY stuff!

One caution with using a vigorous filter output in a container pond -- I used to have my canister filter set up that way on my Rubbermaid stock tank and my comets got a little too excited about playing salmon in the stream. One of them jumped out and spent the afternoon on my patio. Although I was able to temporarily resurrect him, he died about a week later from illness related to the stress of the whole experience. I guess that would be a lot less likely to happen with fancy GF, but it's a consideration worth taking into account. Good luck!

Sure! All you would need is to downsize the container size and pump.




Yea... most bang for our buck. I really couldn't resist 692GPH for $40. I dunno about the less than 10x filtration, lol, I just wanted a big ol' powerhead. Mostly so it's really amenable to larger tank/pond sizes as I slowly upgrade.

As for the leaks, this gallon salad dressing bucket was our prototype. Thomas is going to pick up 6" PVC piping sometime this week and put the thing together. He has some great ideas on how to seal it-- I'll have him post all about it when he gets home from work. If the output is too much for the pond, there is a flow control knob on the powerhead that can lower the GPH. Thomas also made a DIY spray bar that diffuses the water, and I really want to get a small waterbell/mushroom fountain to further the diffusion of the high-power output, as well as prettify the pondling.


Thanks for your replies! We'll keep this thread updated as we go.


Edit: Kristen, thanks for the word of warning. I read that thread about your fish jumping from the pond and I was sad that you lost him.

so i think i'm going to go out to the ranch and see if i can pick up some pvc pipe. i'm assuming that 1 gallon of bioballs will be enough for my hex filter? and how much coarse media do i need? also...for my 35g hex i'm assuming a smaller pump will be necessary...something that pumps about 350g per hour right? and for my future tank outside (at least 50g) i'm going to need something like you have?

also...has anyone used a solar pump for this type of thing? i'd like to try it in the yard if theres a pump worth using...

Some pics of the first edition canister filter:



You can see the small pipe piece used to make the seal inside the canister in this pic:




It has been running with assorted filter pads in it, and a 180 GPH powerhead (bioballs and big pump came yesterday). We'll build the second edition soon.

I haven't looked into solar pumps... but it would be nice, especially if there were no nearby power source. The trouble is that we're using a lot of power for our fish, and solar power systems (with rechargeable batteries for night-time) are expensive. I found a 130GPH solar fountain pump kit for $188... and that's a bit steep for a little pump. Something like that might be nice as a supplement/backup to your main pond filtration (you can buy a pre-filter box to put the pump in, so it is both a solar fountain and a filter), but for a large pump it will become prohibitively expensive.

As for the pump size, I have read that because canisters are so much more efficient, you need less GPH. Also, canister filters are significantly more expensive than other types, so it is much more expensive to get the same GPH. However, you still need enough GPH to circulate the water in your tank so that junk doesn't just settle to the bottom. It is much cheaper when DIYing it... so why not go bigger?

In our case, we wanted a big pump so that we could use it for other purposes later (if it's used in a sump, for example, it will have to lift water against 3-4' of pressure, lowering its output to 400 GPH). People here on Koko's often say that more filtration is always better. Also, the surface agitation from the water return is our sole source of supplementary oxygenation (we're not using an air pump).

There were some concerns about leaks: it's not as bad as you might imagine. When I assembled the filer, I added nylon tape to the threads of the hose barb fittings until they fit snugly inside the "street" (no threads) pipe connectors (the tan-yellow cylindrical shape seen through the plastic in my photos). I applied super glue around the connection, slid the connectors together, and pressed firmly (so that the hose barb fitting was flush with the plastic of the container) until my hands hurt. The fitting in the lid does not leak (I added aquarium sealant last night to be extra safe), but the fitting on the lower part of the container does leak (slow drip). I cut that hole out very poorly, so there's a few spots where I suspected it would leak... I half-expected catastrophic failure. Aquarium sealant will fix that.

Hah, no catastrophic failure yet. We're having a busy week/week-end so DIY canister filter 2.0 is gonna take a little while. You'll have to wait for the bomb-proof fancy edition.

cough cough lol been waiting for updated pics of the filter, been waitin patiently........ lol ok i havent been, but i was wonderin have you guys got a chance to work on the fancy version 2.0 yet?

Yea... about that...

Okay so our lives are a little crazy at the moment--- Peguin's moved ALL of his stuff into my apartment because his apartment leases don't overlap, and we just got back from a busy Memorial Day weekend (his birthday weekend) and I have a test on Monday...

The second reason why we've been lagging is because we haven't been able to find parts. Thomas wants 6" PVC pipe, but NO ONE uses it except for contractors, so local hardware stores don't carry it. And then, of course, every time we go to the hardware store he sees a different container that he wants instead.

I will encourage him to work on it more.

lol, dont worry i was jus givin you guys a hard time. but i know home depot only carries 4" pvc pipe but carry 6" caps, go figure. check and see if you know of a locke supply out there. they are a pretty big chain that caters to more of the contractor demand. they carry it in 6" but you will have to get it by the stick (10'), will be round $20 or so. get the stem wall stuff, its thinner walled but will do the job. or, what i would do, after your test on monday, go around to sites that are being built. like houses, apts, offices, whatever...just talk to some of the plumbing contractors and ask them for any scrap that they have.....lil time, no money, equals a happier penguin and joy! and that way you guys doesnt have to redraw up the plans.hopefully that will work out, if not, drop me an email and i will send you guys some.

There's a lot of new apartments going in within 1/2 mile of here. I've dug through construction scrap piles before... I'm surprised I didn't think of looking there for PVC! Thanks for the advice!

Update on the Mark I canister (gallon salad dressing container):

After acquiring a drastically underfiltered overstocked 50 gallon tank, we hooked up the Mark I canister to our Mark II pump (still hasn't been made ), which if you'll recall from the design list pumps 692GPH.

Well... uhm... it's not going so well. We had the Mark I running with a Penguin 660 powerhead (170GPH) just fine, but it appears the enormous amount of pressure from the Rio+ 2100 is too much for the thin, flexible plastic of the container. It's bulging and changing the shape of the holes, which is causing leakage... we've done some damage control but it's still leaking quite a bit (about 1 gallon per hour loss).

Lesson learned: if you're going to get an exorbitantly powerful pump, do not use a flimsy container!

Suddenly the construction of the Mark II seems a tad more urgent.

cool, i hope that you find some over there in the scrap piles to continue on with the project. sounds like you need it more than ever now with the problems with Mark I.

I recently made a canister filter using a clampable tupperware container, some hosing and a submersible pump. They are really very very easy to make and the principles behind making a filter are very simple (water forced through a sponge). However, I personally would discourage people from making their own canister filters as it is likely to end in tears. I think the overall cost of making it is only about 5$ cheaper than if i would have bought a Fluval 105 and I constantly have problems with the tubing (water is pumped out at a slower rate than it enters hense the canister fills with water is flows over the clamps).

To summarise it was lots of fun to make but save yourself the hassle and buy a proper canister filter unless you want to worry about the high possibility of leaks/high pressure leaks.

I made an internal filter a while back using a plastic bottle, it works really well. I think that would be the 'base' model of what you're working on
The design is pretty cool! I'm going to show my brother in law, he's handy and loves fish tanks....I'm sure that has to be a good combo.

I know a small clamp-top container would work alright, and I saw a how-to for it, but the gallon canister filter packs a lot of filter media, and the flow rate we're running (over 600 GPH) would cost many hundreds of dollars if done with Fluvals. The container I'm using leaks from the lid, even though I wrapped it with lots of nylon tape before assembly, because the threads aren't meant to hold pressure (it's a gallon Caesar dressing container, after all).

So, our design works well for small tanks (the extra water 3" water height of the 55 gallon adds pressure) and at relatively low flow rates (I'd say 300 GPH is good).

Our total cost to date is about $50. Once the Mark II is built, it will bring us up to around $75 ish, more or less. The reason that we're getting high pressure leaks is that due to an unforeseen acquisition of a 50gallon tank with three enormous plecos, four cichlids, and a large gourami practically without ANY filtration forced us to use the prototype with our Mark II pump, which pumps an impressive 692GPH. The Mark I canister was never designed for such pressure, due to it being our PROTOTYPE.

I appreciate your advice but personally it is NOT a hassle. Once we acquire the supplies for our Mark II canister, which will be made out of 6" PVC piping with quick release tubing connections, we won't have to worry about leakage.

A comparable Fluval (Fluval FX5) that pumps 607 GPH costs over $300.

$75 and you have a pump that pumps 692 GPH??? That doesnt quite add up. "CD-12784 Model 1260 $119.99" That is a 634 gph pump from a reputable web dealer and that is one of the cheaper ones I found.

Rio+ 2100, 692GPH. $38.99, Big Al's.

http://www.bigalsonline.com/StoreCatalog/c...e=0&offset=

Big Al's description says 675GPH, but the box says at 0' max flow is 692. At 1' lift it pumps 666GPH.

I guess you're just not looking in the right places.

That is amazingly cheap, good find. My question to you would be then, do you think it better to have the water spending more time in contact with the media (lower flow rate) or to max out your flow rate and have more water going through but having less time in contact with the media?

For the sake of the nitrogen cycle, it is better for the water to have more time in contact with the filter media. For the sake of a clean tank, is is best to have a higher flow rate. This is why the larger HOB filters tend to have multiple parallel media chambers (as in the Penguin 350 vs the Penguin 280: same design, but the 350 splits its flow into a left and right media chamber) OR one VERY WIDE media chamber (Aquaclear 110), so that the flow slows down a bit as it passes through the media.

Our new 55 gallon tank we acquired, though overstocked (read Joy's thread: New Tank!), is reading 0 ammonia and nitrites, so our setup is working for us. If it becomes a problem, splitting the pump's output into two parallel filters will decrease the flow rate through each filter, and increase the filter media capacity. The tank is also VERY clean with all that flow: the pump is at one end of the tank, and the spray bar (outflow; see my "DIY spray bar" thread) is at the other, so that everything is pushed towards one end of the tank.