Converting Spare Aquarium into Sump or Refugium?

[Vaesive]

But you would still have the issue of the filter and pump working at different rates. One or the other tank would overflow. Or the canister would end up running dry and that would burn out the impeller pretty quickly.

I think andy was suggesting you set up the tanks as a traditional main tank and sump with overflow and return pump, and if you wanted the cannister to provide your filtration set it up separately to one or the the other of the tanks.

Sorry, im not great at explaining what i see as the issue.

Ooooooooh. Ok, I completely missed/misunderstood that part! That would actually simplify the setup immsensely and I'd still get to use my glass inflow and outflow! I'll have to do some additional thinking but I think that would work just fine.
Thank you!

 

[Andy Sager]

If the flow from your 407 and the return pump didnt match exactly would one tank get drained and the other overflow?

You got this on the nose. If the input doesn't match the output, you wind up with a drained tank on top and and overflowed tank on the bottom. It gets worse if there is a power failure.

 

[Andy Sager]

Ooooooooh. Ok, I completely missed/misunderstood that part! That would actually simplify the setup immsensely and I'd still get to use my glass inflow and outflow! I'll have to do some additional thinking but I think that would work just fine.
Thank you!

I can make the thinking a little easier . I believe the canister filter is pump driven not gravity fed but by having it above the tank where the water draws from will decrease the overall flow and having it below the intake increases the flow due to lack of pressure. When you are using a filter to feed water from one tank to another, you have the issue of needing to clean the filter at some point and before you do that, the flow rate will decrease and there will be extra pressure on the filter pump causing it to burn out faster. There is also the issue of the power outage. By using the filter in one tank only, when the power goes out, there is no flow. If you have the intake and output in different tanks at different levels, gravity will play a part and backflow to the lower tank. By using the overflow, if there is no water going into the tank, there is no water going out of the tank.
Once you get the flow set with your sump pump, you can use the canister filter in either the main tank or sump to polish and filter the water. It's recommended if you don't use a check valve in the return line, you either set up the return above the water level of the top tank or drill a small hole into the return line just below the water surface so that should you lose power and the water starts to backflow, the hole will suck in air and break the siphon. ( Just some more tricks to keep water off the floor. )

 

[Aiken Drum]

The impeller on fluval canisters only drives the return. The input is gravity fed via syphon.

 

[Vaesive]

I can make the thinking a little easier . I believe the canister filter is pump driven not gravity fed but by having it above the tank where the water draws from will decrease the overall flow and having it below the intake increases the flow due to lack of pressure. When you are using a filter to feed water from one tank to another, you have the issue of needing to clean the filter at some point and before you do that, the flow rate will decrease and there will be extra pressure on the filter pump causing it to burn out faster. There is also the issue of the power outage. By using the filter in one tank only, when the power goes out, there is no flow. If you have the intake and output in different tanks at different levels, gravity will play a part and backflow to the lower tank. By using the overflow, if there is no water going into the tank, there is no water going out of the tank.
Once you get the flow set with your sump pump, you can use the canister filter in either the main tank or sump to polish and filter the water. It's recommended if you don't use a check valve in the return line, you either set up the return above the water level of the top tank or drill a small hole into the return line just below the water surface so that should you lose power and the water starts to backflow, the hole will suck in air and break the siphon. ( Just some more tricks to keep water off the floor. )

I had to look up my filter after things @Aiken brought up and the Fluval 407 is indeed gravity fed. I'll probably pick up a Check Valve next time I go out; finding a fitting for the bulkhead was, for some reason, a massive PITA but I got it. I managed to completely snap off the part that hangs off the back of the tank though so I'm currently repairing it with some silicon rubber -.-

Seriously, I appreciate both your help so very much! I may just set up the main tank with the filter and get it cycling since everything else is ready to go now and just get the sump all set up on a future date

 

[Andy Sager]

I had to look up my filter after things @Aiken brought up and the Fluval 407 is indeed gravity fed. I'll probably pick up a Check Valve next time I go out; finding a fitting for the bulkhead was, for some reason, a massive PITA but I got it. I managed to completely snap off the part that hangs off the back of the tank though so I'm currently repairing it with some silicon rubber -.-

Seriously, I appreciate both your help so very much! I may just set up the main tank with the filter and get it cycling since everything else is ready to go now and just get the sump all set up on a future date

Well, that's a new one to me on the filter. As I said, it's been a while so new stuff has come onto the market. Glad Aiken was able to help.

For what it's worth, if the overflow is made of plexiglass or plastic, silicone would not be the best repair material. There are special glues available for all kinds of plastics that you should be able to pick up at your local Home Depot or Lowes. Just ask a clerk for the glue for Plexiglass. I've used JB-Weld, Weld-on and Loctite brands with great success. The package will say PLASTICS or PLastic bonder on it so you don't confuse it with all the other glues these companies make.

Sounds like a plan for the sump. The good news when using a sump is that it can be added at anytime when you are doing an overflow box. Keep us posted.

 

[Vaesive]

Finally got all the parts gathered and setup and did some testing with the overflow and the return pump and things seem to be running! I decided to mock a power failure to see how the system would respond and mark the "safety level" fill line in my sump and got that nailed down. The only issue I'm having now is the overflow seems to change it's gph on startup? Like, one time things run fine and the speed with the overflow and the return pump are in perfect sync but the next startup the overflow doesn't drain well and is full of bubbles and constantly bubble gurgles into the sump which backs up the water output which slows it down which puts me at risk of the display tank overflowing. I have the little air tube that breaks the siphon at the top of the pvc pipe that goes into the bulkhead as instructed.

If I cannot manage to get things to start up in sync every time I may just attach the return pump to the glass edge of the tank at a higher spot near the safety line in case of a power failure. Any water backflow into the sump will fill it back up safely and when power returns the return pump will continue to pump water to the display tank as long as water is above the safety line. Once it gets below it should stop feeding water to the display tank preventing the display tank from overflowing in the event the overflow is not properly keeping up.

I'm currently doing daily water changes to leech out the lime and stuff from the concrete as well as the tannins from the driftwood; here's a photo of the background I made for the tank as tax for all the help you all have provided

 

[Andy Sager]

I can't tell for sure from the picture but if that airstone is on the side of the tank where the overflow is, that may explain the uneven flow rate and the bubbles in the overflow. Move the stone to the opposite side of the tank.

 

[Vaesive]

I can't tell for sure from the picture but if that airstone is on the side of the tank where the overflow is, that may explain the uneven flow rate and the bubbles in the overflow. Move the stone to the opposite side of the tank.

Nah, the problem was the various connection jerry-rigging I did to get the overflow output to convert to 5/8" tubing causing an air vaccum inside. I went back and got some 1.25" tubing and replaced the whole thing with it and it solved the problem; it was just very difficult to install because that stuff is stiff as hell even after heating it up with a heat gun or soaking it in boiling water.

Anyways, the whole thing is started up and running smoothly and I even got a backflow preventer installed on the return pump so I can fill up the sump to a normal level! I got all the substrate and stuff in and now I wait a week for things to settle since my pH is finally returning normal until my buddy can give me some of his aquarium water! I'll post photos once the tank settles over the week!

 

[Andy Sager]

Nah, the problem was the various connection jerry-rigging I did to get the overflow output to convert to 5/8" tubing causing an air vaccum inside. I went back and got some 1.25" tubing and replaced the whole thing with it and it solved the problem; it was just very difficult to install because that stuff is stiff as hell even after heating it up with a heat gun or soaking it in boiling water.

Anyways, the whole thing is started up and running smoothly and I even got a backflow preventer installed on the return pump so I can fill up the sump to a normal level! I got all the substrate and stuff in and now I wait a week for things to settle since my pH is finally returning normal until my buddy can give me some of his aquarium water! I'll post photos once the tank settles over the week!

Okay. Yeah, Jerry rigging things tend to lead to needing to make adjustments. It's always better to jerry rig into larger then smaller plumbing.
Glad to hear about the check valve. They have saved many a floor from a flood.