Comments on: The Quick and Easy Aquarium Overflow

By: Christobal

Christobal — Sun, 21 Dec 2008 00:52:05 +0000

Instead of using the water diffuser I drilled 1/4” holes around the PVC at the level I wanted. I don’t know if this limits the flow though…

By: ha hahhhhahaha

ha hahhhhahaha — Wed, 10 Dec 2008 01:54:13 +0000

i am from New Jersey but wow. that is ghetto. i have one pretty ghetto but you beat me hands down. i am sure it functions very well and a good thing it hangs on the back so it’s not in your face…. lol happy fish keeping

By: Marcel

Marcel — Mon, 24 Nov 2008 17:27:43 +0000

Hi tod, I think your system would work. I would pay close attention to the water levels when you pull the power plug. Starting the siphon initially may be more difficult since there is so much more vacuum needed to start the flow. Make sure you have a bulkhead in the bucket as well to keep the water level in the bucket at around 1 inch deep, this should maintain your siphon.

I’m really interested to see how it works, please post your results! The biggest complaint so far has been that the over flow takes up too much room, so if this works people may have another option.

Thanks again Tod! Lets see the pics!

By: TOD

TOD — Sat, 22 Nov 2008 04:51:51 +0000

I am new to the diy overflow, but i made one of these designs the other day and it works but i need to use bigger pipe to get enough flow to match my pump. anyway i was thinking that it would be easier to just put a bucket under the tank on top of sump/ refugium and have drain hole in bucket same as pichter and drain right into sump/refugium. wouldnt that work and create a stronger syphon with the tank drain well below the tank? or am i not seeing the big picture. it cant overflow your bucket since water will stop draining at desired water level. seems to me this would work and give more options instead of trying to find something that fits behing your tank. PLEASE let me know if there is something i am not seeing so i dont flood my home. TKS

By: Marcel

Marcel — Mon, 06 Oct 2008 17:35:49 +0000

Thanks for reading Paul,
there is a good diagram made by Rob_Bozuk in the canada fish tank forums here, http://canadafishtank.com/smf/index.php/topic,9.0.html.

The siphon will not break because once the water pressure has reached equilibrium in the jug vs the pvc tube, no water will flow out of the tank until more has been pumped into the aquarium.

By: Paul

Paul — Sun, 05 Oct 2008 15:39:43 +0000

Can you please explain how the siphon will not break? Sorry if I sound stupid but i’m a little confused Diagrams would help. thanks!

By: Marcel

Marcel — Fri, 26 Sep 2008 15:36:11 +0000

Thanks Bigworm175! Glad you like it! Did you get any pictures? I’d like to start a gallery of other people’s versions.

Daminh, I would not try any modify the the HOB, the plastic is too brittle to cut or drill, and glue never sticks either. This system will work fine on a 29 Gal. I’d say use a 10 gal. glass tank or decent sized Plastic Bin as your sump while you experiment. Good luck!

By: daminh

daminh — Wed, 24 Sep 2008 01:04:59 +0000

I have a 29 gallon tank with a HOB filter made by CPR. Any ideas on how I can make an overflow system for this?

By: Bigworm175

Bigworm175 — Sun, 21 Sep 2008 21:56:42 +0000

I just finished making this overflow that feeds a 10 gallon sump/fuge/place for my equipment. This was not very hard and MUCH cheaper than a commercial product that does the same thing. My reef is now much less cluttered with equipment, I have a place for water changes, and it added about 8 gallons to my total water volume. I also love the surface skimming that skimms the scum form the surface and allows more light to reach my corals. Great design! Thanks!

By: Clay

Clay — Mon, 11 Aug 2008 15:42:54 +0000

great article, simple design! there are 2 keys to your overflow not breaking a siphon during a power off or otherwise: you said to place the hose at least half way down the pvc tube AND place the other end in the jug. by placing one end of the hose half way down the pvc, it places it BELOW the bottom of the external jug (key #1). if placed too high, the siphon will pull too much water out of the pvc overflow and air will enter a break the siphon. the other important direction that was only implied, is that the other end of the hose (in the jug) must be BELOW the top of the drain fitting so that it is always immersed in water. (thus when you prime the system with your cup of water, this water needs to cover the bottom of the hose, otherwise it won’t work.) If the hose slips and ever moves above the top of the drain fitting, air will enter the system when the water subsides during a power off of the return pumps and it won’t restart. the rest is all physics - turn off the return pump and water will siphon and drain into your sump until the water inside of the pvc and the external jug hit the same equilibrium level equal to the top of the drain fitting. when it hits this point, water will no longer drain into the jug and it will also not drain backwards from the jug into the pvc.

the only danger is if the power is off long enough that water in the jug evaporates below the hose end - but I would think your siphon is the last thing you’ll be worried about if you have a power off that long!

also, don’t forget to keep the free end of your air line above the end inside the vinyl hose, or you’ll get a second siphon going that could get messy!