How To Pump From An Undrilled Tank To Another and Back Again

[Character85]

I NEED YOUR HELP! All my previous setups have been AIO tanks. I unfortunatelylost my Redsea E-260 during Hurricane Ida. Thankfully many members saved my coral colonies and fish. I want to set up a 75 gallon tank as the tank I was gifted brand new unused. I was considering putting a small 10 gallon tank alongside as a refugium in conjunction with a Clearwater V2 algae scrubber. The tank is not drilled and im unable to gave a sump under the tank. I would have to pump out to the tank and scrubber alongside the dusplay Any advice on how to plumb to both tanks and back to the display? I have limited height clearance in my basement. Since the stand/bar is very tall, I will be unable to use gravity to feed the drain on the scrubber and or refugium back to the Seaswirl return. Can I use an additional inline pump to feed water from the drain of the scrubber and or refugium back to the Seaswirl return to the tank? How do I calculate the head pressure etc. Thoughts ideas and input welcomed.
Thank you to the many who helped and took in my family members in my time of need. You know who you are and thank you again!

 

[blaxsun]

Without knowing any details of the 75-gallon tank (AIO, overflow, returns, etc.) it's hard to advise.

 

[DCR]

One of the two flows (to or from the scrubber/refugium) needs to be gravity flow. You cannot reliably pump to and from the refugium with two pumps and keep them in perfect balance. Either the refugium will overflow or it will go empty and flood your main display tank.

You could use an overflow box (siphon) on the main tank and put the refugium below your display tank and pump the return back to the display.

 

[Character85]

It's a bare tank undrilled standard 75. 48"x18"x20". I have a filter/pump in each corner. 2 Tunze Comline filters in opposite corners, a Tunze Comline Skimmer, and Tunze Nano Wavebox in the other two corners. I was going to put 2 separate pumps on the sidewalls of the tank that would feed back into the tank by mounted 3/4" Seaswirls for extra dynamic flow. I would like to have one Clearwater V2 Algaescrubber hooked up to one of the pumps that returns via one Seaswirl. The other side I would like to go to either a 7.5 AIO or a standard 10 gallon that I would use as a refugium. The return pump in whichever tank would get hooked up to the other 3/4" Seaswirl returning yo the tank. I would put an additional pump on either side of the display to power a chiller fir the 6 months or so out of the year I would use it. My question/focus is mainly how to plumb and pick the right pumps for:

To and from DT and scrubber
To and from DT and refugium

 

[bobnicaragua]

Back in the day everyone used an external overflow box. Here’s a pic of one of my old tanks. Notice the box in the upper left corner.

Gravity is the only option.

 

[Character85]

Are those HOB overflow boxes reliable to use? The optional tank I would use for a refugium is a Lifegard 7.5 gal AIO... I can afford a cheap 10 gallon if needed but this tank I already have... Does the fact it's an AIO where water drains to rear filter chamber matter?

 

[bobnicaragua]

Are those HOB overflow boxes reliable to use? The optional tank I would use for a refugium is a Lifegard 7.5 gal AIO... I can afford a cheap 10 gallon if needed but this tank I already have... Does the fact it's an AIO where water drains to rear filter chamber matter?I

They’re pretty reliable and were super common in the past.

The most important thing for the sump is that it’s big enough to hold all the water that will drain into it when the power is out.

 

[ScottJ]

You can check out Life Reef Overflows; https://www.lifereef.com/siphon.html
You might want more than a 10gal sump, though. A 20gal will work. This might be more than you are looking for, BUT I think he has the best overflow systems around.

 

[Character85]

Thank you everyone... This would simplify everything