2 display tanks running on the same filtration system (sump)

Skinner'sReef · Sep 30, 2019

Hello all,
Im going to start building a cube tank and stand tomorrow, not sure what demensions yet, I want to do something a little different with it though.
Im going to put this new tank next to the tank I currently have and I was thinking about how I can run both tanks through the same sump. Has anyone done this before and is there any reasons why its not a good idea? The new cube tank I want to build is going to be small so I wont be adding very much more water maybe 10-15 gallons so I don't think im going to need a bigger skimmer or anything like that im more curious on how im going to get the water to flow correctly. Do you make it one circuit of water flowing through both tanks then to the sump or do you do 2 seperate circuits where both tanks have a siphon to the sump and a return pump back to DT? If I put the new cube a bit lower than my current tank the water can siphon from my main DT into the new cube,then siphon from the new cube to the sump and be returned back to the main DT. The new cube tank will never get any fresh water from the sump in this case. I don't have anything set in stone yet im Just curious if anybodies done this before and how they did it, or any helpful ideas or tips are appreciated. Sorry if this is drawn out and redundant, hope it all makes sense haha, Thanks.
I will keep you guys updated with the build once I get this thing figured out.

Timfish · Sep 30, 2019

I've set up systems both ways and either works fine. Getting the flow right is a bigger issue if you're feeding the large tank to the small tank to the sump. Personally I would have two seperrate circuits. I would suggest doing flow charts on paper with both configurations and figure out the flow rates and look what happens if the pump(s) are turned off. The one thing you want to avoid is having any kind of valve or restriction anywhere on a drian or siphon to reduce the risk of something clogging and causing a flood.

WVNed · Sep 30, 2019

I am doing 3. a 240, 75 and 20. 3 separate pumps and separate returns. Make sure your sump can handle the drain back when power is cut.
Mine is a 100 gallon tub.

Michael Lane · Sep 30, 2019

Pretty much the same situation here. I have a primary 265 display, with auxiliary 15 and 20 displays. They are all plumbed into the same sump, with sufficient capacity for all 3 displays losing power. I have 1 return pump for the main display and 1 shared return pump for the 2 smaller tanks.
It's a lot of plumbing routing into a relatively small sump area, but I'm happy with the fact that I really only have 1 system to maintain.

JMM744 · Sep 30, 2019

120 and 180 both fed from a 100 sump. Each tank has its own return and overflow. Works great..

Skinner'sReef · Sep 30, 2019

Awesome so I will continue on with it then seems like nobody has any negative comments about it. Im going to need a small return pump then ill run 2 separate "circuits" Cant wait to show you guys how it turns out. Im going to have glass slabs cut tomorrow and Ill assemble the tank and stand. Going to be a very simple stand since it wont even require a sump underneath. Thanks for all the feedback!

Skinner'sReef · Sep 30, 2019

The Cube tank im going to build should be small enough I should be able to drain the entire thing into the sump without a flood if for some reason I had to.

NVS · Oct 2, 2019

Quick question on this topic. Is there a reason why you couldn't have a single return pump with a Y where each side has a valve to control return volume? Are the valves even necessary? As long as the pump can't exceed the drain volume, shouldn't this be fine?