Anyone diy a canister filter?

[Oughtsix]

MANY years ago I made one out of a Cornelius Key (stainless steel soda pop keg) and it ran fine and held a ton! I found that doing maintenance on it was such a hassle that I hardly ever cleaned it. I found that my tank was much healthier with a regular old Eheim canister. Then I switched to sumps and haven't used canisters since.

 

[burntrubber]

I run an Ehiem classic with a 5" tray underneath. I check if it's dry every water change day. It helps me sleep better.

 

[Johnez]

MANY years ago I made one out of a Cornelius Key (stainless steel soda pop keg) and it ran fine and held a ton! I found that doing maintenance on it was such a hassle that I hardly ever cleaned it. I found that my tank was much healthier with a regular old Eheim canister. Then I switched to sumps and haven't used canisters since.

Hey oughtsix-very curious as to how you set up the cornelius keg to make it work as a canister for your filter. I've looked at diagrams and I don't know what to keep and what to toss and what to replace the inlet and outlets with. Looks like the perfect container.

 

[Oughtsix]

Hey oughtsix-very curious as to how you set up the cornelius keg to make it work as a canister for your filter. I've looked at diagrams and I don't know what to keep and what to toss and what to replace the inlet and outlets with. Looks like the perfect container.

I just unbolted the pin lock connectors from inside the keg and found some stainless steel bulk heads that I used with barb fittings to connect the hoses (I am pretty sure I ordered them from Grainger and I had to enlarge the holes in the keg a bit... with a Unibit step drill). The supply line went to the top of the keg and the return to tank line drew from the bottom of the keg. I did not know about Uniseals at the time... I suspect they would work quite well in the 3/4" to 1" size and hold the pressure without an issue. I suspect a well build polypropylene bulkhead with thick rubber washers would work too... I know PVC bulkheads won't seal well and it will probably leak. The pump has to be before the keg to push the water through and keep the keg at a positive pressure. I used a fair sized little giant pressure rated pump.

I used a short fat Cornelius keg instead of a taller thinner one because the shorter one fit in the stand under my tank. The shorter fatter ones also have a bigger opening on the top which makes them easier to put the media in and remove it for washing. I used many layers of thick coarse porret foam for my media which worked as mechanical + biological media. With the keg, bulkheads, misc plumbing, pump and foam I was into it for well over a couple hundred bucks by the time I had it working well.

After experimenting with the Corney keg for about a year I decided that a huge capacity canister was not all that I had expected it too be. It really didn't add anything to the tank and was a REAL hassle to clean, so it didn't get cleaned very often which caused high nitrate levels in my tank. Everyone on the web (this board in particular if I recall correctly) told me not to do it and it would not be worth the effort. BUT there are some things that I just have to try for myself!... I did, and they were right!

 

[Johnez]

Everyone on the web (this board in particular if I recall correctly) told me not to do it and it would not be worth the effort. BUT there are some things that I just have to try for myself!... I did, and they were right!

Heh, I know that feeling. DIY canisters in general have a bad rap it seems now a days, most people seem to think it's not worthwhile when sunsuns are so cheap. Experience is the best teacher, if only to cross something off. That Corny keg idea is really unique, tho in my case (75 gal tank) probably truly overkill.

 

[DRUKENMUNKY]

The main points u must consider when attempting this is the pressurized part. I simply used pvc because I had the best chance for a seal using pvc glue. Things like gamma seals unsealed are definitely not reliable if u plan to push the boundaries and use a strong pump. Also realize that with a pressurized canister the media being used is very crucial....the finer it is the faster it will clog and change the amount of pressure on the seals. I have been using my pvc one for maybe 2 years now but I maintain it weekly..I mainly did it for a lot media with a very quiet filter. If u don't want a possible puddle of water in your home I'd be cautious....and maybe even just consider a gravity fed non pressurized style overhead sump. There are reasons why cannisters are not rated for gph....it is because the seals can not handle the pressure. So be cautious ...dont go trying to use 2000 gph and try to build a diy cannister unless u are using a BIG CONTAINER WITH BIG HOSES AND MEDIA THAT CAN NOT CLOG UP FAST. Remember things like using 3/4 inch pvc can handle a max load of 1200 to 1300 gph and jumping to 1 inch will get u maybe around 2200....at little head pressure and wide open media. I tried and failed several times before I built the pvc filter and this was main challenge.

 

[fishdance]

If you don't want to use a sump and are having trouble making a canister then consider an undergravel filter. Far more media and biofiltration ability than any canister.

You can make an undergravel with a sheet of 50 mm sponge and thin layer of substrate if you dislike gravel cleaning. Or look into a matten side filter perhaps.