# DIY Canister Filter



## acrosstic (Mar 24, 2008)

So I want a high capacity canister for a 125 I am hoping to get.

I need to do it on the cheap as we all do and I believe I can create a super canister filter for less than $80 not including a pump or media.

5 gallon bucket w/ lid
egg crate or grit guards
filter floss for polish
Sponge prefilters
bio balls
bulkhead fittings
pvc pipe and fittings.

Bulkhead fitting onto bottom side of bucket. PVC sprays up from center of bucket with one 90 degree fitting.

Using egg crate, I am going to build and glue a box the size of whichever sponge prefilter I can get. The bottom will be glued around the pipe inlet with a top zip tied down after the prefilter is inserted. OR If I can find a large prefilter I can cut to size I will do that like i have listed below.

Another egg crate cut to fit the 5 gallon will sit on top of that. Then a layer of bio balls, which I can find locally for $15 for 500 (which is about 3/4 of a 5 gal bucket). Or this stage could be bio max or whatever you might want to put here. then on top of the bio balls one more cut to fit egg crate to separate the bio balls from the filter floss.

Another bulkhead fitting is attached to the top side of the bucket and the PVC returns the tank (Or you could use tubing).

Fill the bucket with water, then attach the 5 gallon bucket lid and fasten tightly. If the bucket doesn't leak paint its probably not going to leak water, depends on the lid you get, but for $9 plus shipping (which is $8) you can get a water tight "Gamma Lid" which might be worth the peace of mind. Maybe I can find them locally for cheaper.

http://www.pleasanthillgrain.com/gamma_seal_lids_gamma_lid_products.aspx

Also, I doubt it is cheaper, but it could save me a lot of time would be to buy a couple of the Grit Guards and may be a little better fit. These are designed for janitorial or car cleaning where they want the dirt to sink to the bottom of the bucket and not pick that dirt back up in the mop or rag. I'm going to try to find them locally for cheaper.

A bucket $5, bulkhead fittings $20, gamma lid $17, and three grit guards $40 or egg crate $15, (bio balls $15), PVC $8.

$65 not including any media and a little work to get it all together, plus the floss, bio balls, and sponge prefilter probably looking at about $95 total.

So you might be thinking what good is $95 when you add a pump to that your going to end up with the same price as a canister. There is a difference, because you can buy a pump that will filter your tank water many more times per hour than that commercial canister.

This canister would be able to filter huge amounts of water for half the cost. The entire thing is customizable as well eahc stage you choose the filtration.

If I have forgot something in my design plans please let me know.


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## TheeMon (May 11, 2004)

how are you making the water move back and forth? i didnt see any pump mentioned.... or did i miss it?


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## Nathan43 (Jul 9, 2007)

It seems to me that a DIY sump using an old used aquarium would be more efficient and pretty close to the same price. Pretty thought out though.


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## a_c_arnold (Mar 7, 2008)

Just make sure that yours seals are good. That will siphon a lot of water out of our tank if it starts leaking. Make sure that you put the pump after the filter and don''t pressurize the bucket, because DIY makes me a little nervous when using bulkhead fittings and 5 gallon buckets in the house. The suction off of the pump can help pull a vacuum on the bucket and help hold the lid. Keep us updated. You may want to make your intake pretty shallow until you find out if it will leak or not. At least a shallow entake will only cause a small flood.


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## acrosstic (Mar 24, 2008)

Pump after the bucket...good advice I was going to have the pump push the water into the bucket, maybe I should reverse the flow I was thinking about. Water flows in from the top, through sponge then bio balls then floss then is sucked back into the tank. That sound better, because it also puts the part I'd most often clean on the top of the bucket as well as uses gravity to help the water through the stages. Why I didn't think of that I don't know.

The bulkheads are going to be glued and siliconed in place. Those two combined with the gasket should prevent leaking, but I am not going to go deep with the intake to start and I'll set the bucket in a rubbermaid bin to start as well.

A sump may be near the same price, but relying on an old aquarium to hold water makes me just as nervous as the bulkhead fittings on a 5 gal do. Not to mention the additional space I'd have to have, the more complicated construction, and the noise. Most people have a 5 gallon sitting under the tank anyways. Then there is the whole overflow business and I don't want to cut holes in my tank or take away swimming room for my fish or the ugly HOB siphon stuff. I can't touch a sump tank large enough for a 125 for less than $65...so this is cheaper, for me.

The goal is to create a high capacity, high efficiency canister filter using only 5 gal of space and using very little tank space with no HOB. I am worried about the possible amount of bypass the filter could have, I'm interested to see how tight the grit guards slide into the bucket. I may have to cut an old 5 gal bucket into rings that slide securely around the edges to prevent water bypassing the filter. However, if the sponge and floss are cut tightly and I'm filtering say 1000 gph or more I don't think it is a huge deal. I might be able to run a bead of silicone and the egg crate would sit against it and therefore the water would have to flow through and not around them, not sure, gonna have to see.


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## Mcdaphnia (Dec 16, 2003)

Having had buckets that suddenly split on the bottom or sides, I would be sure to use new buckets on a project like this if I was forced to use a bucket instead of large diameter pipe.


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## IrkedCitizen (Apr 26, 2007)

Mcdaphnia said:


> Having had buckets that suddenly split on the bottom or sides, I would be sure to use new buckets on a project like this if I was forced to use a bucket instead of large diameter pipe.


I was typing my reply before and while you were replied.

Now on to my reply.

The problem with using a regular 5 gallon bucket lid is once you pop the lid off to clean it one time you will have to replace the lid to get that complete water tight seal again. And if you use that gamma lid how hard is it to bust that sucker free? How tight does it actually get?

Another reason to not have the pump push water through media is that it creates back pressure which can wear the pump down prematurely. So it is better to let gravity feed the water through the media and then have it pumped back.

Here is what I would suggest building versus using a 5 gallon bucket When I first started DIY for my aquariums I thought the same thing about using a 5g bucket but have since avoided doing so because of reasons like McDaphnia stated.

What I would use if I were you is 4-6" PVC pipe as the "canister" anything bigger than that and the price increases significantly. A picture is worth a thousand words so rather than explain it right now I drew a sketch using windows paint so you could at first see what I am typing about. Let it be known that these sketches are just to show the basic layout. When you plumb it you can compress it together rather then have it stretched out like in the picture to save space.

Don't mind that line across the top it was used as a center line and erasing it was more effort than I wanted to put into it.










A more detailed shot of the return as I really couldn't draw the return in the first picture without covering up needed information. But you can plumb it however you want below that union. Everything above the union that is below the Y fitting should be kept as drawn.










Now I will explain how it works.

Each canister is made of the 4-6" PVC pipe and each one has an end cap at the bottom only. The water enters the end cap via 1/2" PVC piping and then the water rises up by gravity through the media and exits out of the top via 1/2" PVC piping. The two canisters then connect to each other at the Y fitting and then connect to the pump that of course pumps the water to the tank. You can make the canisters as tall as you want. You are pretty much just limited by the height of your stand. Which you then pack full of your media of choice. With this design there are 2 intakes one per canister and then 1 return line. You can vary the height at which the intakes draw in water to the canister such as 1 near the bottom and one near the surface.

This system is designed so that you can run both "canisters" off a single pump and be able to fully disconnect each "canister" from the setup for maintenance/cleaning while having one canister running at all times. Also you can take the pump off the system for maintenance/cleaning or to replace it in case it breaks/fails without having to cut it out..

I would use all of the fittings that are in the picture. The ball valves when closed keep the water inside the canister so you can move it to a place to clean it without leaking/spilling water the whole way. They also keep the intake tubes primed which is nice. The pieces I left white are the PVC pipe. You can either hard plumb the intakes or use tubing it is up to you. In the picture the yellow things are these. By using those you can quickly and easily get into the media by unscrewing the compression nut rather than having to bust off the 5 gallon bucket lid. With this design all the plumbing uses 1/2" PVC pipe and fittings with the only things not that size being the end caps, main canister pipe, and the adjustable nylon plug. You can use 3/4" PVC if you want.

The main advantage in this design is you can alternate cleanings on the canisters so you don't have to worry about causing a mini cycle after cleaning the media from your 1 bucket. You can of course use more then 1 bucket but that is more space taken up within your stand. Plus those 2 canisters using 6" PVC pipe that are say 18" tall could hold just about as much media if not more than the 1 five gallon bucket while using the same footprint.

Disassembly:
1. Close the 2 intake and 2 return ball valves to the canister you want to disconnect. 
2. Once they are closed, open up the unions.

The canister is then separated from the system and you can clean it.

Cleaning:
1. Take the canister to your sink/bathtub/where ever you want. 
2. Drain the water from the canister into a bucket do not discard water. 
3. Unscrew the expandable plug and take the media out. 
4. Rinse the media in the water from the canister that is now in the bucket. 
5. Discard the water.

Reassembly:
1. Put the rinsed media back into the canister.
2. Take the canister back to the tank and connect the unions
3. Open up the ball valves on the intake side and let the water from the tank fill up the canister.
4. Once the canister is pretty much full to where the water exits the return pipe to the pump close one of the ball valves on the intake side to stop the flow.
5. Then put the expandable plug in and tighten the heck out of the compression nut.
6. Open up the ball valve that you just close on the intake side. 
7. Open the ball valves on the return side. 
8. Fill up the tank with water since you removed however much water the canister can holds.

Viola, the canister should then be fully operational. You do it in that order to get the majority of the air out of the canister so it doesn't break the prime.

One thing you would have to do is build some kind of rack to support them off the bottom of the stand since the water enters at the bottom and it cannot sit flat. But that isn't too hard and shouldn't be a problem.

Seeing how the proposed tank size you are wanting to put this on is a 125g you can make two sets of these for a total of 4 canisters full of media with 2 return pumps. Meaning you can clean 1 canister off each system each time you do a cleaning. You would also then have 4 intakes you can put 1 in each corner and then the 2 others spaced evenly in between.

Hope that helps you out a little. :thumb:


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## acrosstic (Mar 24, 2008)

That is a fantastic idea!!!

Why not just set them on their side? They wont roll around the PVC will keep them in place and you have what at least 4' of horizontal space in most stands? So you could build say four 2-3' canisters and use some wood to stack them. Might effect the way it filters, perhaps.

My biggest concern is the compression pipe plugs.

The 6" pipe size is only made in a hollow stem and according to that site can only withstand up to 42 PSI. What kind of PSI can you expect in this system? I'd think upwards of 42 PSI is possible. Those things are $50 too. Four of them = $200, you've priced me out of the project just with the caps. I could just do a sump for that.

Also it appears from your drawing that you have the water entering the bottom of the pipe. I think I'd rather have it enter the top, that way gravity helps the water travel through the media and the gravity help will save the extra wear on the pump (As does having the pump pull the water). Oddly enough swimming pools have the pump push the water into the filter.

I'm thinking about other options for the cap. How about one slip to male adapter glued onto the end of the cap and then a 6" threaded cap screwed tightly with Teflon tape onto the male end. You could unscrew it when you needed to service the canister and it would cost a fraction of what the compression nuts do, and also would likely be much tougher. The only issue might be a big enough wrench to tighten the sucker down and loosen her up.

I like the idea, I just need to cheapen and thus adapt it.[/list]


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## Mcdaphnia (Dec 16, 2003)

Since the cannister is a closed loop, gravity is cancelled out because the intake and return are at virtually the same level.


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## IrkedCitizen (Apr 26, 2007)

Mcdaphnia said:


> Since the cannister is a closed loop, gravity is cancelled out because the intake and return are at virtually the same level.


What do you mean by this? Was this directed at his laying them on the side or toward the design I posted? If it was directed toward my design you can easily put the pump at an elevated height. I drew it like that because if I drew the fittings any smaller you wouldn't have been able to see. Using real PVC pipe you can cram all of those fittings into say a 9-10" span.



acrosstic said:


> That is a fantastic idea!!!
> 
> Why not just set them on their side? They wont roll around the PVC will keep them in place and you have what at least 4' of horizontal space in most stands? So you could build say four 2-3' canisters and use some wood to stack them. Might effect the way it filters, perhaps.


Yes it would change the way they filter



> My biggest concern is the compression pipe plugs.
> 
> The 6" pipe size is only made in a hollow stem and according to that site can only withstand up to 42 PSI. What kind of PSI can you expect in this system? I'd think upwards of 42 PSI is possible. Those things are $50 too. Four of them = $200, you've priced me out of the project just with the caps. I could just do a sump for that.


Those that I linked you to are just to show you what they are. I didn't feel like doing a glorified search to find the ones you can use. The ones I would use and yellow hence why I colored them yellow in the pictures. If you hit a home depot or other hardware store you can ask someone that works there if they have expandable nylon plumbing plugs. They should have them they consist of a yellow plastic frame with a big rubber bushing and have a bolt with a wing nut on the top. When you tighten the wing nut the plastic frame compresses on itself and expands the bushing. There shouldn't be hardly any pressure in this system as the pump is after the fact and gravity feeding into the canisters. Gravity doesn't put much pressure on the PVC pipe.



> Also it appears from your drawing that you have the water entering the bottom of the pipe. I think I'd rather have it enter the top, that way gravity helps the water travel through the media and the gravity help will save the extra wear on the pump (As does having the pump pull the water). Oddly enough swimming pools have the pump push the water into the filter.


Eheim classic canister filters have the water enter at the bottom. So if it has worked for Eheim all these many years with no ill effects then it is perfectly fine for DIY canisters. You can have the canister be like 2" shorter than the waterline in the tank and have the water enter the bottom of the canister and still have it fill up completely. The water will try to level out with the waterline in the tank and since the canister is shorter than the waterline it cannot level out thus water keeps feeding through the filter. Also having the water enter through the bottom makes it so that water has to go through all of the media with the water entering at the top there is no guarantee that the top corners sections of the media will get any water. Also elimates the chance or air bubbles collecting at the top of the filter.



> I'm thinking about other options for the cap. How about one slip to male adapter glued onto the end of the cap and then a 6" threaded cap screwed tightly with Teflon tape onto the male end. You could unscrew it when you needed to service the canister and it would cost a fraction of what the compression nuts do, and also would likely be much tougher. The only issue might be a big enough wrench to tighten the sucker down and loosen her up.


It isn't the part of tightening those screw on caps that is the problem it is busting those suckers free. Like I typed above you can comparison shop for those expandable nylon plugs. I simply linked you to the top link that came up when I googled them.



> I like the idea, I just need to cheapen and thus adapt it.


It's easy to do it on the cheap. It is just how easy you want to be able to get inside to perform maintenance. The harder it is to perform maintenance on a filter the less likely you are to clean it regularly.


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## acrosstic (Mar 24, 2008)

Well, those compression plugs need to be cheaper, if I can find them much cheaper then I can see that being the way to go. If not, I'm going to see if the threaded way will be water tight without teflon tape. If so, they wont be so hard to open with a pipe wrench. I wish there was an easier way, but those are my only two options right now.

I agree with you on the intake at the bottom, the only thing is maintaining the canister is harder all the bad gunk is at the bottom. so everything has to come out just to wash off the sponge. Still I do like that the water is forced to move up through all the media, so I will probably do that.

I was at Lowe's tonight so I stopped by the PVC area. I found 2' pieces of 6" PVC for drainage ($5 each) but NO fittings. I mean there were drainage caps with holes, but no fittings of any kind.

4" PVC they had plenty of options, including the male adapter and the threaded cap. I didn't see the compression fittings, but I was on a time crunch. Also, there is a specialty plumber supply about 2 miles from my house. I got an odd sized adapter there one time, so they will likely have or could get anything I need. I'll try Home Depot first.

I determined laying them on their side is not really getting you much, at some point length only allows you to add more bio balls or bio max, more sponge or more floss is just more to clog the sucker up, so like 1-2' is probably PLENTY of space for the media, and if you do 2 or more canisters, no problem.

I'm trying to figure out the bulkheads. I mean a bulkhead is how much money? and it could leak. So why not glue PVC adapters from 4" down to 1", then connect your intake. Even with 2-3 fittings, glued PVC is much less likely to leak than a bulkhead that have been inserted into a cut hole on a rounded surface and is prevented from leaking with a rubber gasket. One bulkhead per canister instead of two, and the lone bulkhead would be on the top, and not the more important bottom one (The one which if it failed would flood your house).

Here is my little drawing. With the pipes, adapter fittings, bulkhead, PVC scheme etc. I didn't worry about the PVC fittings, they are easy enough.


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## IrkedCitizen (Apr 26, 2007)

acrosstic said:


> Well, those compression plugs need to be cheaper, if I can find them much cheaper then I can see that being the way to go. If not, I'm going to see if the threaded way will be water tight without teflon tape. If so, they wont be so hard to open with a pipe wrench. I wish there was an easier way, but those are my only two options right now.
> 
> I agree with you on the intake at the bottom, the only thing is maintaining the canister is harder all the bad gunk is at the bottom. so everything has to come out just to wash off the sponge. Still I do like that the water is forced to move up through all the media, so I will probably do that.
> 
> ...


You have the general idea. How you set it up is completely up to you. My drawing was just a rough sketch and isn't law but more of a guideline to get you in the right direction.

To get the water into and out of the PVC canister you can drill and tap the end cap and PVC pipe near the top to accept threaded PVC fittings which you can then glue into place with PVC glue.

Do with it how you will. I merely gave you some food for thought. :thumb:

:fish:


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## Mcdaphnia (Dec 16, 2003)

IrkedCitizen said:


> Mcdaphnia said:
> 
> 
> > Since the cannister is a closed loop, gravity is cancelled out because the intake and return are at virtually the same level.
> ...


It was directed to this comment about pump wear.



acrosstic said:


> ....that way gravity helps the water travel through the media and the gravity help will save the extra wear on the pump ....


Because the water drawn from and the water returned to the tank through the intake and return pipes are nearly the same level, any effect of gravity on the water falling through the intake pipe is cancelled out by the effect of gravity on the water rising through the return pipe.

:idea: Pressure increases at a rate of 1 atmosphere (14.7 PSI) for every 33 feet. In any unsealed filter, such as a wet/dry, that means there is not much pressure added. Cannisters are sealed, so the pump can add a great deal of pressure. To get an idea how much, you could shoot the return water straight up against a wall through a sweeper jet nozzle and then measure how tall the wet spot is. :fish: This is not for inside the house. Set up outside where you can't hit anything, especially electrical wires. I have to admit I'd done this it the house, but it was OK, my wife wasn't home. :wink:


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## acrosstic (Mar 24, 2008)

I'm not too concerned about the pressure as long as everything is sealed well.

When I get the 125 is when I'll have to start the project. I'll post pics when I get there.


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## IrkedCitizen (Apr 26, 2007)

Alrighty, keep us posted.


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