DIY Mini Canister Filter

[Orion]

I've had a small HOB filter on my 5 gallon shrimp tank for some time now. It does it's job farily well, but I had been wanting to do something more effecent for filtration. As this is a shrimp only tank, a lot of crud doesn't get sucked in by the filter just because my cherry shrimp aren't that messy. Plus, I just love doing a good DIY project just for the sake of doing it.

Over time of searching the net for various things I recall seeing plans and idea's for a DIY canister filter. While the idea intreaged me, I had always thought it to be too much of a hasle to really bother with. Then I cam across plans for a 'nano' canister filter just for small tanks. I was blown away by the simplisity of said filter, and decided that it was time to give it a whirl.

So I went shopping last night for a container to act as the main canister houseing. This is where the pump and the media would be. I chose to use a 'Lock and Lock' brand container.



I was rather happy to see that my local wal-mart carried these. I had read account of others not being able to find these and were using regular zip lock containers. The zip lock containers apparently were good about not letting air in, but not so good at keeping the water in. The Lock and Lock containers not only have the four clips to hold the lid on, but also a silicone gasket to further help create an airtight/watertight seal. Anything can conseavably be used for a container, as long as it can be airtight. I opted for the square container so that I wouldn't have to drill, or seal up any holes made on a round surface.

Total cost so far, $2.97 per container, I bought two 'just in case'.

The most pricey item for a project like this is going to be the pump. But thankfully my years of hording up old parts and equipment have paid off some what, and I had a few pumps on hand that I could choose from. I decided to use an exo-terra repti-pump. It was made to power a small water feature in a reptile setup. It has a low flow rate, and small size so it is perfect for this project.

I decided to place the pump inside the actualy container for a few reasons. First of all so that I didn't have to have any equipment showing in the tank, and secondly to keep things neater by keeping the 'filter' as compact as possible.

I drilled a hole in the center of the lid for the pump outlet to fit. It was made just slightly smaller then the pump nozle to help get a good grip around it. Since the pump was going to be inside the filter, I had to make a way for the power cord to fit as well. I drilled a smaller hole for the power cord to fit though. I cut the cord, fed it though the hole, then reconected the cord with butt conectors and a bit of shrink tubes just for safely sake. I've found out plenty of times that water and electricity just don't mix well.





So now I had pretty much got the parts done to return the water too the tank. Now I was left with the question of how to get the water from the tank to the filter. I'm the type that if I'm going to use something for a project, I would like to leave it as intact as I can. This way incase the project doesn't work out or what ever, I can still use the parts in other projects, or even back for the original use. I took the pipe from a sponge filter that the sponges went around for the water intake. Agian I drilled a small hole in the side of the container just big enough to squeeze the pipe though. This left me with a good place on the outside of the filter to be able to connect my lines too, as well as even distribution of water going into the filter.

This is the part from the sponge filter.






Since this was all a test, I hadn't really done anything to permentialy bond the pump and intake pipe to the container. I used my hot glue gun to secure and seal around all the holes and equipment. This is just a temporary measure , one just to make sure that the thing is going to work at all and would be feisable to continue, and secondly so I can test things and be able to make adjustments to the equipment without much headache. If things go well I will replace the glue with silicone for a more permenate and better seal and bond.





So we are all glued up and ready go. Already found the first problem: Anyone thinks a fluval is difficult to prime try one of these babies! It's not so much that it's difficult as it is tricky. Of course by useing standing water that was lower than the top of the filter didn't help any by putting gravity aginst me. This shouldn't be as much of an issue once it's on the tank because then the water will actualy be a little bit higher than the filter. So I got everything hooked up, primed and ready to roll. After finding a small air leak in the top where the power cord runs though and re-sealing that, it worked great in the kitchen sink. I let it run for two hours, and it didn't loose a bit of water from the filter except where it was supposed too (the filter return ).

So far this project has cost less than a pack of smokes, and from the trial run looks to be a sucsess. All that's left is to figure a way to get the plumbing from the tank to the filter. I do know that for the intake that's going to be in the tank I will be useing the same part off of the sponge filter as what's in the container. This will still give good flow to the canister, and protect the shrimp. The return that's in the tank is likley to just be a small elbow of sorts.

The media isn't going to be anything fancy. I may put a layer or two of floss at the top, but most is going to be biological media. I've several of the plastic pot scrubbers that will work great, and eventualy I may break down and get some actual bio-rings or something similar to those.

I'll still keep this updated as I progress along from this point.

For larger versions of this canister, bulkheads would make a wonderfull addition to it. This would allow one to get the good intake and return holes already in the canister while still keeping a water tight seal around them. I had thought about making some out of PVC, but seeing as how small the tubes are for this filter, it would be more of a challange to get them up to 1/2 inch size and back down agian than it would be worth.

Any comments or questions are always welcome.

[jbfootin]

Great post! Make sure to post pictures of the finish product, plumbed to the tank with media in it. I don't think you chose it for this reason, but for instructional purposes the fact that it is a see thru canister helped!

Could you use a power head for the pump on this? Do you need to put in baffels to make sure the flow of the water is even through the media?

[Orion]

The clear container just happened to be by chance, not design.

Sure you can use a powerhead. Anything that will push or pull water would be fine as long as you can figure out how to conect it. Baffles would work well I'm sure, but I'm not interested in 100% water flowing though the media. The media I have in mind is going to pretty much cover side to side, so there won't be a lot of lost water anyway. Still enough water movement though the media to keep the bacteria happy. They do make a small canister for turtle tanks, but you could use it however you'd like. It's around $30, so not bad to begin with. I'm doing this more for the love of DIY than to really improve on the design or save money anyway. So feel free to take the idea, and re-design and improve upon it all you want!

[Orion]

I made some media racks, mainly just to keep the media in the highest area of flow rate. Took all of about 5 minutes to do. For material I used eggcrate and zip ties to hold the 'legs' on the bottom part.





Here you can also see the top rack which hopefully will keep the media from just floating around the container.

[Orion]

Now here is some fun parts. Decideing how to make the intake fit on the tank, in the tank, and makes it's way back down to the canister.

For the part that goes on the back of the tank I used two 90 degree PVC elbows placed togeather with a small section of PVC.



All PVC used is 1/2inch in size. Then I took two plugs, and drilled a hole in each of them. This is for the ridged tube's that I used to attatch the flexable tubing to each side of the PVC. The holes in the PVC plugs were just a hair to small, so I took a heat gun to warm up the PVC a little bit (Be very carefull! It would be easy to heat them too much and cause them to melt a little bit.) just enough to where I could push part of the ridged tube in it. Doing it this way, when the PVC cooled it helped create a good seal aroud the tube which so far hasn't needed any additional sealing.





The short side is to go in the tank, and the longer one is for the outside of the tank. I made the one that's on the inside of the tank shorter due to the layout of the plants and other decor in the tank so it wouldn't be too long.

Then I placed the PVC plugs in each end of the PVC 'U', squeezed each cap down onto the 'U' with some channel locks. I didn't have to use PVC cement because the plugs were tight enough fitting as they were, but the use of the cement wouldn't hurt anything here.



Next I squeezed on the tube I'm using for the filter on the ridged tube that goes to the container, and then placed the other end that goes into the tank on the other side of the 'U'. The flexible tube I'm using is just about the same OD as the other pipes, so it took a little effort to get them on, but well worth it. I also used zip ties around the part that goes inside the tank just to be sure that part of it will not slip off and allow room for the shrimp to get sucked into the filter.

This is what the finished product looks like:


The other end of the tubing secured to the canister:

[NoDeltaH2O]

very cool Orion. What do you think the turnover rate is going to be? And how small is the shrimp tank?

[Orion]

The shrimp tank is a standard 5.5 gallon rectangle. I haven't a clue what the turn over rate would be as I don't even know the GPH rating of the pump. But I do know that it's not much. I would guess it would be somewhere between 25-50 gallons per hour? Lets take a happy mediumish of 35, so that would turn the tank over 7 times an hour. That would be optimal, so reality maybe 5? IMHO quite suitable for this shimp only tank, as it does see much love and gets a WC every week.

This is a great learning time for me, and so far it's going rather well. One issue that I'm running across is that any air trapped in it (and it's seeminly difficult to get all the air out) is traped at the top, and not able to escape, unlike traditional canister filters where the motor is at the very top of the liquid chamber. I've not quite figured out a good way to help this air escape, or even if there is a good way other than removing the pump from the container all togeather.

[The Cable Guy]

Take an airline valve and glue it into a hole in the top to bleed the air off. Once the air comes out, shut the valve for normal operation.

Just my $.02

[Orion]

I was thinking of something pretty much along those same lines cable guy, thanks. The only problem with that is that's just one more hole to take care of. Still, I think it would be worth it.

For a return to the tank I made a small spray bar from the different pipes and connections that I had laying around from other filters. So far it's doing well. Hopefully get some pics of it tonight.

It's been running for over 12 hours now with no apparent problems, and no leaks. I may go ahead and replace the glue with silicone, and then let it run on an empety tank for a week or so with full media just to see how well it will hold up and preform under 'real world' conditions. I expect a good outcome from this.

I'm already thinking of a bigger DIY canister. I have a few pumps that have 1/2" MTP conections on them, so it would be super easy to rig these up because I can use all 1/2" PVC, which is a lot easier to come by localy than the small pipes used for filters. Some people have tried using a 5 gallon bucket, but have had trouble getting the seal on the lid to stay. Other's have used 4-8" PVC pipe for the main container. Either way, they all work on the same principal as the smaller version more or less.

[Orion]

Hot glue does not make for a good sealant. Or at least one that will move the least little bit. But I knew this. The glue around the power cord has since shrunk some and letting water out. Not a real biggie, as I didn't expect to be able to use the glue forever.

Going to try to silicone all the parts and pieces in this weekend, let it cure for a few days and start it on another test. So far, I'm still very pleased with this.