# Eheim plumbed to overflow



## gsander (Dec 18, 2004)

I have 90 gal tank that i used for a reef tank prior to making the switch to freshwater planted. I have to admit, I loved the reef tank, but a freshwater planted tank is going to be much more rewarding. Anyway, my question is if anyone has ever used a Eheim canister filter attached to an overflow. The tank has two drilled holes in the overflow which I have sealed up with two bulkheads. I was thinking about removing them and attaching the Eheim to the bulkheads. I would keep the water level high in the overflow so there is not aggitation. Water would be drawn down into the canister just as it is now. Has anyone tried this? I thought this would be a great place to hide heaters and plumbing. I can drain the overflow to work on this project without removing water from the tank.


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## niko (Jan 28, 2004)

Gsander,

Theres is no problem doing what you describe.

You may want to be careful to really make sure there is very little agitation of the water flowing through the comb of the overflow. A Durso pipe maybe. The only reason to do that is to make sure you are not loosing CO2 due to the agitation. It's not a big problem actually but CO2 escapes very easily when the surface is turbulent.

A thing to watch is floating plant matter blocking the overflow comb. Some people put an additonal strainer around the comb.

Hooking up the Eheim to the bulkheads is not a problem. It would be practical to have ball valves and unions (Eheim or Home Depot) installed in the in and outflow filter hoses so you can remove the filter if you need. Also maybe it's a good idea for the intake hose to be of a greater diameter so the filter never has problems sucking water.

One last thing - I assume you will have the discharge of the filter close to the overflow. When your tank becomes densely planted you may have problems with the flow because the plants obstruct it. That may not be the best positioning for the outflow. There are 3 options to resolve that:
- extend the outflow further
- have a the filter suck water from the bulkhead overflow but discharge through a separate hose on the opposite side of the tank (best option I think)
- install a spraybar running along the back glass of the tank.

--Nikolay


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## gsander (Dec 18, 2004)

thanks alot!


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## Phil Edwards (Jan 22, 2004)

gsander,

I've got an Eheim Pro II 2026 hooked up to an 80g tank in much the way you describe except without the overflow. I wouldn't worry about any agitation with the overflow since the Eheim is basically a closed loop. There won't be any uncontrolled/open system cascading down the overflow since it has nowhere to go if the pump's not running. 

Anyway, a word of caution about current. You're better off splitting the intake into both holes and using the spraybar that comes with the filter as an output. The pump on the Eheim isn't sufficiently powerful enough to make a current in a 90g tank unless it's choked back a lot. I have to have use powerheads in the tank currently in order to get enough water movement. Rather than use the spraybar another option is to just have the U tube in the tank and direct the flow from that horizonally with the attachments provided.

Even with that your best option is to get two filters and have one hooked up to each hole. 

Best,
Phil


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## discusdave (May 24, 2004)

gsander said:


> I have 90 gal tank that i used for a reef tank prior to making the switch to freshwater planted. I have to admit, I loved the reef tank, but a freshwater planted tank is going to be much more rewarding. Anyway, my question is if anyone has ever used a Eheim canister filter attached to an overflow. The tank has two drilled holes in the overflow which I have sealed up with two bulkheads. I was thinking about removing them and attaching the Eheim to the bulkheads. I would keep the water level high in the overflow so there is not aggitation. Water would be drawn down into the canister just as it is now. Has anyone tried this? I thought this would be a great place to hide heaters and plumbing. I can drain the overflow to work on this project without removing water from the tank.


I've done it multiple times and it works great. Plumb in the Eheim Quick Disconnects and you'll love it. I've done this with at least 4 reef ready tanks. Heaters, pH probes, digi thermometers all go in the overflow.


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