How to make connected frag tank without drilling.

[Jake_the_reefer]

I am looking to add a lowboy frag tank to my existing 20g tank but I want to connect them to the same system, how can I connect two tanks with no sump and no drilling? Is this even doable? What I'm thinking is a hob overflow box, then have the overflow drain into the frag tank, the frag tank will have an aio like design where the return pump is behind a weir going back up to the main tank. The frag tank could possibly be considered a sump with a filter sock. Sorry if this is a confusing all over the place post I'm just brainstorming

 

[ScottieB]

I kinda see what your saying, problem I see is there’s no margin for error. A blocked drain or pump failure, power outage and you have water all the floor.

Maybe having some failsafes built in like leak sensors, auto shut off outlets on water level sensors, etc... might help but that’s just adding more layers of potential failure.

 

[Jake_the_reefer]

I kinda see what your saying, problem I see is there’s no margin for error. A blocked drain or pump failure, power outage and you have water all the floor.

Maybe having some failsafes built in like leak sensors, auto shut off outlets on water level sensors, etc... might help but that’s just adding more layers of potential failure.

That's a good point. Because dont hob overflows rely on running perfectly? A syphon fail can flood the display tank.

 

[Silent]

Most use something like the aqua auto lifter pump to remove air and keep siphon going and to restart siphon after power outages

 

[WVNed]

It could be made to work. Is there enough height difference between the tanks to get the water from the bottom of the HOB overflow into the other tank.

 

[andrewkw]

I know the thin glass of the lowboy scares some but the cleanest holes I ever got were drilling a lowboy. It really was not harder than drilling a thicker tank - In reality it's easier, you just have to be careful.

 

[Jake_the_reefer]

It could be made to work. Is there enough height difference between the tanks to get the water from the bottom of the HOB overflow into the other tank.

The height difference would be about 2 or 3 feet.

I know the thin glass of the lowboy scares some but the cleanest holes I ever got were drilling a lowboy. It really was not harder than drilling a thicker tank - In reality it's easier, you just have to be careful.

I would have no issue drilling the lowboy I just cannot drill my display tank.

 

[Jake_the_reefer]

Duplicate oops

 

[WVNed]

You would do it like a sump then. Drain down cant overflow the bottom. Empty return cant overflow the top.
Hob overflows do work. I used one for a year and a half. They do require attention though.