DIY Multi-Canister Filter

[Olly613]

Looking forward to seeing the plan. My canisters are obviously commercial ones that I plumed together, and it is running in series. But the concepts are similar. I have planed to do something similar to your design, on a larger scale, for a 1000+ tank that is on my long term planning list. I will be looking forward to the opportunity to plagiarize your design.

No, your system looks great, and you plumbed well by the looks of it. And the fact that you've had your pump going for ten years is encouraging, so I think I'm gonna have mine push water instead. It is understandably better for flow, and the pump damage seems minimal if at all existent. Also, plagiarize away, haha. With all the help I'm getting here, there very least I owe you, and others, is few design ideas. Also, not sure when you're doing this project, but I'll tell you this: when I do build this in it's final form (May), I'll take pics to document the process, and more so the end product. Once it's all done, I'll make a new thread with the final plans, my basic instructions, and the results. I'll also try to include suggestions as to how one might improve the build process or design.

Okay, so here's what I currently have (sorry if I missed something, let me know). Visually pretty similar, and the diagram is equally crude, but ...


- Plan is still to use 4 canisters despite only showing 2 (just easier)
- I now have the pump up top pushing the water.
- Added 4" Wye's (accidentally labelled "Y" in the diagram, duh) with reducers. I'm not sold on this necessarily, as it is more expensive, but I figured it might keep the flow more direct, and more importantly I think in simplifies the method by which 1.25" pipe connects (before, it was basically just a hole with necessary sealing. This should reduce the risk of leaks and reliance on silicone)
- Chose 4" pipe for canisters and 1.25" pipe for the flow pipes, but will likely change this from 1"-1.5" based on the pump fittings/power. (By the way, previous estimates for 6" volume were wrong I believe, made a stupid error in converting. So the volume drop in using the 4" was nowhere near as drastic, and indeed much cheaper)
- Haven't included my media assembly, as I'll probably just experiment with that based on leftover supplies and whatever seems to work once it's in operation. But sponges and ceramic/plastic bio media is what's planned, with some form of blocking device or cage to stop media from flowing through the system, and for ease of removal for cleaning.
- For the air bleed/valves in the caps, I think the easiest way I can fix this, and also maintain it, is to have about a foot of air line tube (~0.25" I think is typical) with either a topper or small valve. Essentially, open the tube and let the water (or siphon the water) up the tube and close it again. This is easy to do, cheap, and you visually monitor if you're getting a big air pocket too.

I think that sums up the major changes (?), though I also included a rough diagram as to where the assembly will be placed, and a cost break down of the major PVC components (so this excludes pump, filter media, and additional pipe/fitting to run to aquarium). At present it looks like a $200 dollar assembly, which is about double what I was aiming for originally, but a couple things to note (aside from the fact that I'm terrible at projecting costs ):
- The wye & reducers aren't necessary at the canister tops, really just for my sanity given that this is my first real PVC project, and I don't want to have to worry too much about sealing in pipes at a 90deg angle through a hole (plus it keeps everything flush on the inside so that media cages slide more easily). So eliminating these could cut costs if you're more confident in you're plumbing skills.
- Also, I have two people looking into ways I can get this stuff cheap. First, relative who works in a scrap yard who sees stuff like this come in often enough (trying to get a pump this way in particular). Anything that's fairly clean and unused (way more often the case than you may think) I'll grab up. Secondly, a friend who's family owns a big franchise hardware store can get big discounts on hardware, so I can buy most new stuff through him.

Note, in my cost table, i used approximate prices for the caps and the reducers. This is because I can't seem to find these items in 4" at my local hardware stores, so I'm still looking around (the reducers I likely need to use two in sequence, but I just can't find the 4" female caps like the one used in this link ruddybop provided:
http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/62265-diy-pvc-pipe-canister-filter-step.html
The only place I saw that had these was USplastics or something, and they were very expensive, so if they don't exist cheap somewhere, I may just use the cheap-ish male caps and rig up my own easy twist handle - any suggestions or links as the what exactly they are called/where to get them cheap would be super).

For PVC projects like these, do I need to worry about additional curing time or specific bonding agents given that it needs to be aquarium safe?

So, still looking for anymore input, especially given the redesign. Anything that should be scrapped, added, or changed - just let me know and why.

Thanks

 

[Olly613]

Oh, and if I have to buy an external pump, what are a couple worthwhile brands that aren't too expensive (between the 800 -1500 gph im looking at)?

 

[pshtex]

only thing i can recommend is to re think the junction after the canisters where all the water goes back to one pipe. u have a T joint and opposing currents hitting each other head on at this juncture. i would think that that would cause a large amount of flow loss. but that is just my 2 cents

 

[pshtex]

what if each return pipe remained separate there is no real reason that they have to be joined together after the canisters with the pump in its new location.

 

[Olly613]

The only reason I can think to have them all come together is for the sake of cost, and not have to buy 4 times the amount of supplies to return it to the tank. But you still have a good point with the 'T' possibly reducing flow (especially considering with 4 canisters there will be 3 of those joints down there). I'll look first if I can make it angle together in someway instead. I won't bother doing up a diagram for it, but that's a very good point, thanks!

(This is why having others review one's work is useful - they spot the things you miss!! )

 

[MatthewN]

I have seen a lot of DIY filters and cans. i i think that this one looks the best that i have seen as of late. Very good idea and i think it would work well. Looks like its going to take up some room tho.lol.. well cant wait to see a finished product. Heck if it works out well i might buy one for a 500gal ply/glass tank i want to start building next year. Keep us updated, i look forward to seeing the finished setup.

MattN
AKA AZ

 

[Olly613]

I have seen a lot of DIY filters and cans. i i think that this one looks the best that i have seen as of late. Very good idea and i think it would work well. Looks like its going to take up some room tho.lol.. well cant wait to see a finished product. Heck if it works out well i might buy one for a 500gal ply/glass tank i want to start building next year. Keep us updated, i look forward to seeing the finished setup.

MattN
AKA AZ

Thank you for the encouragement. And yeah, it won't be small, but in my case it's going behind a wall in a different room, hidden from sight so I'm not worried. That being said, I would bet with some clever manipulation of the elbows, you could easily make is smaller, or at least flatter/taller/etc. as would best fit the space available.

Anyway though, as I mentioned I will make a dedicated thread for the build and final plans when they are done.

 

[zachsta18]

Another solution to the problem with the air making noise is to switch the intake and return. Put the intake at the bottom, , return at the top, and assuming that you have an air tight seal it should be okay, I think? I don't know, but that is how my eheim works, and its EXTREMELY silent. Another option would be to literally flip the whole canister upside down, with the cone at the top. That would solve the air issue because there would be no top area, and the bottom would just fill up with water which does flow. Don't worry, the water at the bottom would still be moving due to current from the 1000 gal/hour pump. I think that should do the trick.

 

[Olly613]

Another solution to the problem with the air making noise is to switch the intake and return. Put the intake at the bottom, , return at the top, and assuming that you have an air tight seal it should be okay, I think? I don't know, but that is how my eheim works, and its EXTREMELY silent. Another option would be to literally flip the whole canister upside down, with the cone at the top. That would solve the air issue because there would be no top area, and the bottom would just fill up with water which does flow. Don't worry, the water at the bottom would still be moving due to current from the 1000 gal/hour pump. I think that should do the trick.

Thanks for the suggestion.

I think with the air pocket you have an idea there - though I suspect whether its pushing water up through the system or down, the "cap" area will still have an air pocket due to air slowly accumulating. And as tempting as it is to flip the system, unfortunately it means either making it tough to clean out (one of the primary goals of my system) or reconfiguring to interior of the canister to run the water up through an inside smaller pipe which flows over the small pipe and down - which reduced my media volume. That being said, I think I'll 'try' the small air line thing - alternatively if that does not directly work out, I could run those airlines up and into the tank/into the return pipe for the tank as a form of a bypass. Assuming it's a small enough diameter, the flow loss through the canister should be negligible, and the cap should still unscrew given that the airline is flexible. As a backup plan to that, I think the earlier proposed ideas of either a tire valve or simple screw valve are pretty easy too. Sufficed to say, lots of options!

That being said, you've given me a couple ideas that I shall look into, thanks!

 

[Oughtsix]

5 gallon capacity, food grade stainless steel, sealed, rated for a much higher pressure than you will ever need all for about $25!