# Two canister filter set-up of intakes and outputs



## chefdanrd (Apr 26, 2019)

I have a 75 gallon aquarium with a Fluval 406 canister filter. I just purchased a Fluval FX6 as a second canister filter for more flow/filtration. My question is what would be the best way to set up the intakes and outputs of both canisters? What configuration would be most effective? It is an Mbuna tank with 90 pounds of rocks that run the length of the tank about a foot high.


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## nodima (Oct 3, 2002)

it comes down to trial and error due to differences in how your rockwork is set up. That said, I generally try to get a smooth circular flow through a tank. One way to accomplish this is to set up both returns at the top left of the tank, pointing across the surface. Both intakes are low on the left. What happens is the water flows across the tank, down the far wall and back across the bottom towards the intakes. With a lot of rock, it may be helpful to have the smaller return low on the right side, pointing across the bottom to overcome the rocks blocking things.


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## ironspider (Dec 5, 2017)

I have no idea what the "right" way is, my way seems to work well. I have two canisters, cascade 1000's, intakes are in the rear opposite corners of the tank, say about 2-3" from the glass. For the output, I use the spray bar at the top, right at the water line, and the other one, just a directional piece just under the surface in the corner. I get enough surface agitation and I keep the intakes close to the PFS substrate and most of the garbage gets sucked up, I never vacuum the top of the substrate.


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## chefdanrd (Apr 26, 2019)

nodima said:


> it comes down to trial and error due to differences in how your rockwork is set up. That said, I generally try to get a smooth circular flow through a tank. One way to accomplish this is to set up both returns at the top left of the tank, pointing across the surface. Both intakes are low on the left. What happens is the water flows across the tank, down the far wall and back across the bottom towards the intakes. With a lot of rock, it may be helpful to have the smaller return low on the right side, pointing across the bottom to overcome the rocks blocking things.


 Thank you for your input it gives me a foundation to experiment from. I think that is a good idea to try this configuration to start with both intakes on one side and the outputs on the other. It looks like the FX6 has a larger input than the one on the 406. First, since there is more of an open area in the rocks (where you can see well through the rocks) closer to the center (about one-third the length of the tank), would it make sense to put the largest input there in order to pull the most volume of water through one side of the tank to the other (depth of tank) and the smaller input further to the outside of the tank where the area it is more obstructed? Second, the output on the FX6 is quite a bit larger than the one on the 406. Since it will have the greatest amount of flow, would it be best to locate that output closer to the outside wall of the tank and the smaller output inside of that or the other way around?


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## chefdanrd (Apr 26, 2019)

ironspider said:


> I have no idea what the "right" way is, my way seems to work well. I have two canisters, cascade 1000's, intakes are in the rear opposite corners of the tank, say about 2-3" from the glass. For the output, I use the spray bar at the top, right at the water line, and the other one, just a directional piece just under the surface in the corner. I get enough surface agitation and I keep the intakes close to the PFS substrate and most of the garbage gets sucked up, I never vacuum the top of the substrate.


 Thank you. That was helpful.


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