DIY overflow and sump with a twist. will it work??

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oxidessc

Aquarium Advice Newbie
Joined
Jun 13, 2011
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Location
solihull, england
right guys, first post on here and its gonna b a interesting 1.

first off my tank is a 28 gallon nano with a few frags in atm. basicly im gonna build a pvc overflow pipe, ive done loads of research into that and thats not the problem. now im just wandering as im running a canister filter at the moment and im trying to do this on the cheap. would it be possiable to have the overflow run to the sump then the original intake from the canister filter taking water in from the sump then pumpin it back to the tank. i already know that the canister filer pump is powerful enough to get the water back to the pump?

its a origional idea (well i havent seen anything like it on forums or vieos on youtube) just wandering peoples thoughts.

thanks. stu.
 
It would most likely work, the only problem I would see is that either the canister would pump out all the water out of sump because the overflow doesn't pump out fast enough, or the sump would overflow because the overflow pumps in water faster than the canister can pump out.
 
That problem would have to taken into considerarion when selecting the diameter of the overflow tubing wouldnt it? So the flow in equals the return flow.
 
This sounds like it could work, just as mentioned above your overflow would have to match the gph/power of your canister so the water is coming in and going out at the same rate.

A problem I do see is what if the pump or canister cuts out? Either the sump will overflow or the canister will run dry, both of which are not good things to have happen
 
ill try and get some plans together when i get time but i cant see the overflow failing because it will be 1 that keeps syphon even when the power goes out

YouTube - ‪Nano Lagoon (DIY Overflow)‬‏

this isnt me but its what i plan on building.

it will only work when the water is above the overflow level. so if the power goes out the canister filter will stop and the water will only overflow untill it goes below the intake pipe.

Another advantage i thought of is that with the canister filter having a mechanism in it which makes it easy to remove the input and output tubes without loosing all the water out of it ( kind of like the fluval 205,305,405) then it will prevent a back syphon if the power does decide to stop.

again ill try n get pics n plans up n see what you all think. thanks for the comments tho.
 
this is a quick design of what it will look like when done. only basic cos im no expert on paint. oh and i no the overflow pipe is just 1 downpipe on my diagram but please relate to the video to see what it'll actually look like. all the other tubes are just basic single lengths of silocone hose.


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right guys, first post on here and its gonna b a interesting 1.

first off my tank is a 28 gallon nano with a few frags in atm. basicly im gonna build a pvc overflow pipe, ive done loads of research into that and thats not the problem. now im just wandering as im running a canister filter at the moment and im trying to do this on the cheap. would it be possiable to have the overflow run to the sump then the original intake from the canister filter taking water in from the sump then pumpin it back to the tank. i already know that the canister filer pump is powerful enough to get the water back to the pump?

its a origional idea (well i havent seen anything like it on forums or vieos on youtube) just wandering peoples thoughts.

thanks. stu.

I actually did that several years ago. <Great minds think alike! :)>

Unfortunately it did not work very well. A canister filter has a small pump which is designed to run without a "head" pressure. Basically, the intake & output has to be at the same level, so the water pressure in the intake can push the output water back up to the tank. When the intake is in the sump & the output in the (higher) tank, the pump will have to work hard to overcome the pressure differential. In my setup, my head pressure was ~ 3 feet. A HOT Magnum was unable to pump anything at that pressure. My old Magnum 350, which is rated at 350 gph, was able to do ~ 100 gph as a sump pump (measured). I used that for a while, but upgraded to a real pump that can do 1000 gph rated & ~ 800 gph actual.

You might be able to use a canister as a return pump if:
You have a big canister &
You don't have a lot of height difference between the sump & the display. <The canister will be perfect if the sump is at the same level.>

At any rate, I would suggest testing how your canister will perform at a height differential before going too deep into the project.
 
Also commenting on the overflow design: <The pic is rather small so I might not get all the details right.>

It is true that when the power is out, the water in the display will only drop down to the level of the over flow & stop. However, you would have lost the siphon in the overflow. When the power comes back on, the return pump will pump, but no water can get back to the sump & you will have a flood. This is a fatal flaw!

To do the PVC overflow safely, you need to have a way of preventing the loss of siphon. You normally need 2 U-joints - one inside & one outside the tank to preserve the siphon. I think the video has it, but I can't see the outside loop clearly enough to see if it is failsafe.

You can also use an alternate design where the intake is at the bottom of the tank & you control the water level with a loop outside the tank. This is a bit safer for preserving siphon but has a draw back as well.

Personally I would use 2 siphons, each capable of of carrying the entire pump flow. <A 1" ID pipe will do 750 gph safely.> I would set the 2nd siphon slightly higher (say 3/4") than the first (but still beneath the tank rim). That way, when the 1st siphon entrain air (and you will, esp. with skimming from the top), the rising tank water can be drained by the 2nd backup siphon. You can then quickly see by the water level that you need to reprime the 1st siphon. <With white PVC, you cannot see any air in the siphon loop & cannot prevent accidental siphon breaks before floods!>

Maybe I am too obsessive about floods ... but working with 100 gal of water makes me very cautious ..... belts & suspenders all the way!
 
thanks for the reply jsoong. im gonna build the overflow first n test it in a bucket in the bath tub. i think ive seen a video on youtube of somebody doin this with the same overflow and it working when u turn the shower head off (simulating a power out) it seems to work. the only real was of judging this i suppose is to do it myself. then ill get onto the return pump.

Just to let u no i have the canister filter running at the moment on the same tank i am going to be running the overflow system on and its working fine. the reason i am looking to upgrade to a sump is with the additions of a few more corals i belive im going to need more filter space and the ability to add a skimmer at somepoint too. also will b able to make a auto top off system hopefully.

oooo just a thought. probably a silly 1 but i have a maxi jet 400 pump lying about. how about pumping the water up to the canister filter which could be but at the same hight as the base of the display tank? its gonna b a maze but im just wandering if i can do this with all the bits i have at home lol.
 
The only way to see if your canister can handle the head pressure is to test it. Mine did not do too well, but yours might work better.

I wouldn't put 2 pumps in line (that is what you are thinking with the maxijet?). It is just too difficult to balance all the flows & you are just asking for failures down the road. If your canister is not giving you enough flow, why not run the maxi jet in parallel? You just need an extra return line.
 
hey good idea. i didnt think of running them both. could use 2 return lines then 1 actual nosel in the tank having both lines going to it. That way creating more flow in the tank from a single output. hmm sounds like a plan. gonna build the overflow n sump box monday/tuesday so we shall go from there.
 
I didn't read the entire thread, so apologies if someone asked this. But why not just run it right back into the sump? You'll get lots more contact time w/ the media in a slow moving sump. Mine does. It puts some wear on the canister since they are meant to be gravity fed but if you elevate the sump somewhat it works
 
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