# Using a overflow/reef aquarium with canister filter



## ZombieEinstein (Aug 17, 2015)

Has anyone ever used a canister filter with an overflow-style aquarium, or can they think of _any_ reasons why it wouldn't work? I know sump systems are usually employed with over-flow designs, but I want something more quiet than a sump.

I'm getting back into the hobby after a several year hiatus for school, so I'm basically starting from scratch. I used to keep African Rift in a 55gal "rock desert", but I'm planning on a planted aquarium this time, and want it to look extra special. I'm thinking cube or cube-ish, somewhere between 30-75 gallons (probably 40-55g), preferably glass (fewer scratches), rimless, in-line heater, a nice LED fixture with day/night cycle (maybe the one Fluval makes, with simulated weather lighting), basically nothing "in the tank" besides plants and fish. Still don't have a clue what species are going in, I just know I want it to be a real eye-catcher - an underwater jungle - with little to detract from the show.


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## DJRansome (Oct 29, 2005)

A rectangle allows you to stock more fish than a square...stock by length of the tank, not gallons. I find haps, peacocks and Tanganyikans do better with plants than mbuna.

You want 48" or more for most Malawi.


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## nodima (Oct 3, 2002)

I've used canisters on a drilled tank, but in conjunction with a sump. I've also seen tanks drilled and canisters plumbed in using bulkhead fittings on the bottom of the tank. However, I recall talking to a friend who has a tank business about putting a canister intake inside a overflow, and he cautioned against it for a number of reasons, not the least of which was the possibility of water levels dropping enough in the tank to cause filter to pump air, could happen if water levels drop too low, or simply forgetting to shut filter off when doing a water change. Additionally, the drilled holes would need to be plugged.

Overflow tanks are a bit more expensive and it would be much simpler just to buy a standard tank if you don't want to run a sump.

If the primary purpose of the tank is to be planted, I'd recommend a tank that it more than 12" front to back - so if you are thinking 55, go 75 instead. That extra depth allows significantly more room for plants and to come up with a pleasing look.


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## ZombieEinstein (Aug 17, 2015)

I'm probably going with South American this time, simply because their expected water quality and their general behavior is a little more conducive to planting. I remember something like the 'length' rule, but the goal of this tank isn't fish species diversity. I'm probably going to stick with the more square base, because plants usually like the room to root in all directions.

I hadn't thought about levels falling below the overflow, but that is a good point. I was planning on using the drilled holes as the inlet and outlet for all filtration, I'm good with plumbing, so I can probably make even the a concentric-pipe system work. A lot of the drilled tanks I'm finding online include a basic sump, might put the canister on that instead. The problem with a lot of included sumps (besides noise) though is that they all seem to be designed for salt water - a section for a protein skimmer, maybe some mechanical, and then everything else is done by a macroalgea refugium. All kind of useless for freshwater, at least without some amount of chemical and biological filtration (a la bioball or ceramic pieces), and more refined mechanical.
I'm not too worried about expense. I'm not going to be buying everything all at once, and I have up-to $1,200 budgeted for the tank (though the goal is to not spend nearly that much - that is just the contingency for if I have to get it custom built). As I said, extra-special.


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## nodima (Oct 3, 2002)

The other issue you may run into with using drilled holes for canisters is the need to include shut off valves in line in order to service the canisters - depending on how you design it, you might run into water spills every time you service the canister.

The issue you raise about a sump for SW vs FW is not a huge factor - very easy to make a sump with FW in mind, and many times the actual set up is similar to the SW version, with some creativity with PVC and egg crate it is quite easy to adapt. Look into poret foam also.

Your filtration needs in a planted tank are far less than those in a fish only tank, as the plants use many of the waste products we try to filter out. Where they are similar to fish only tanks are around circulation - which is effectively needed to spread out CO2 and fertilizers throughout the tank.

Even with a planted tank, I'd still argue for something longer than say 30" even in a cube, as there is a lot more you can do in terms of aquascaping.

While I share your goal of minimizing equipment in the tank, hiding a single intake and outlet for a canister is not too difficult, particularly in a planted tank. Keep in mind, many of the planted tanks photographed have the equipment removed for the photo shoot, and don't look that way normally. Glass diffusers for the outlet are available as well.


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## Opulent (Jan 20, 2012)

As the tank already has the drilled holes in the weir, I really can't see any reason not to use it as intended and have a sump. I bought a marine aquarium so I could set it up properly with a sump and mine is almost silent. The only noise I can hear is a quiet hum of the return pump, which you certainly can't hear when the TV is on. No splashing or water crashing noises with mine - you just have to set it up properly.


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## Narwhal72 (Sep 26, 2006)

If you hook up a canister to an overflow system, the cavity within the overflow essentially becomes the sump. As water evaporates, the water level within the overflow box drops. This creates a number of issues in practical use:

1. It's a much smaller volume than a typical sump. This means that normal daily evaporation will drop the water level much further. Requiring more frequent top off to keep the canister running.

2. If the overflow does evaporate enough that air gets into the canister it can lose prime. Generally the prime will restart automatically once the overflow is filled back up automatically. But some models may form an air gap around the impeller and the canister may need to be primed manually.

Although it can run quieter than a high flow sump, maintenance needs will greatly increase so there is a major tradeoff between using it with the overflows vs. a standard siphon.

Although a longer tank certainly makes for a very impressive display, cube tanks can also look good if aquascaped properly. I generally prefer a center focus aquascape so the fish swim around the decor in circles. I find this gets far more activity out of the fish and the center decor breaks up line of sight which reduces aggression. I used to have a 4'x4'x30" cube tank that was an excellent tank for Tropheus and some Large Haps that used to inhabit it.

Andy


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