Can I plumb two separate systems into one large refugium, making it one large system?

[Seancj]

I'd like to add a 30 gallon frag tank and sump to my existing 80-gallon tank. I'd like to do this by having the 30-gallon tank partially drain into a 55 gallon refugium currently hooked up to the 80 gallon but also partially drain into its own sump. So, basically both the 30 gallon and the 80 gallon sharing the same refugium, making it one large system. Will this work or will there be flow/drainage/evaporation issues? I'm hoping this will work and allow me to instantly utilize the 30 gallon tank since it will share the already mature water and live rock from the 80 gallon/55 gallon refugium system and no worry about cycling. Basically just adding about 40 gallons to the system.
The 30 gallon will have its own return pump, skimmer, and heater. I'll ball valve all connections so that if ever needed, I could close off the 30 gallon tank from the 80 gallon tank, making it its own isolated system.
The 80 gallon tank partially drains into the refugium and its own sump in a similar fashion.
Thoughts?

 

[Reef By Steele]

Issue I see by running through two sumps is getting balanced return. If you can regulate return to equal out flow no problem. I had tanks in two separate rooms run to a combined sump wet/dry trickle years ago but all the overflow lines went to the combined system and the return pumps went to the specific tanks so the water level remained constant.

 

[Reef By Steele]

If you could configure it to run through new sump then to existing sump and return pump in existing sump you would avoid having to regulate return pumps as only as much water is returned would go through overflow.

 

[Seancj]

If you could configure it to run through new sump then to existing sump and return pump in existing sump you would avoid having to regulate return pumps as only as much water is returned would go through overflow.

So only the return pump from the existing 80 gallon system would be returning water to both tanks? I had thought of this, but I don't think my existing return pump has the GPH to handle the combined water volume.

 

[BeanAnimal]

Basically, any configuration will have to have all of the water drain to the same place.

 

[MoshJosh]

I would have both tanks share the sump then plumb the refugium into the sump separately.

 

[Reef By Steele]

So only the return pump from the existing 80 gallon system would be returning water to both tanks? I had thought of this, but I don't think my existing return pump has the GPH to handle the combined water volume.

You can have two return pumps in the existing sump, one for each tank. The tanks will only overflow the volume added to them. I ran 4 pumps on my old system, 2 to each tank, but all of the water coming from the tanks ended in the same location.

 

[MoshJosh]

You can have two return pumps in the existing sump, one for each tank. The tanks will only overflow the volume added to them. I ran 4 pumps on my old system, 2 to each tank, but all of the water coming from the tanks ended in the same location.

I have 2 tanks connected to 1 sump and this is how I am running it. Each tank has their own dedicated return pump.

 

[Reef By Steele]

Pretty crude drawing, but here is a representation of how I think it will work best and safest.

 

[Reef By Steele]

If not enough room for two return pumps you can y off of one larger, but you lose a lot of GPH when you divert return pumps.

 

[Seancj]

Thanks everyone for the input so far. I see the need for both return pumps in the one sump. My current return pump doesn't have the gph to drive both tanks and the refugium. Gravity draining from the new sump to the refugium to the old sump will not be possible though. I don't want to drill the 30 gallon's sump.

 

[Seancj]

Thanks everyone for the help. I decided to skip adding the 30 gallon's sump into the system. The 30 gallon now drains directly into the refugium that drains into the original main sump. I placed the return pump for the 30 gallon in the sump with the main return pump as recommended. I also placed the 30 gallon's protein skimmer in the sump as well. Now there are two. So far, all is working well.