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Overflow box issues

IOnceWasLegend

IOnceWasLegend

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I've run into my first problems with the new build on my 50g ZooMed low boy frag tank:

1. There is a rim on this tank, which I was dumb and didn't consider.
2. The pre-drilled drain hole is not big enough for the Eshopps Prodigy M overflow box I got.

Overflow hole.jpg


I'd prefer not to drill the tank if I can avoid doing so (since I have no experience doing that), and I'd need to remove at least part of the brace around the top to boot. Does anyone have any suggestions for how to plumb this?

Alternately, if there's any services around that drill tanks, how bad of an idea is it to cut away part of the rim to let the overflow box sit flush?
 
Coral reefer said:
It’s pretty easy to drill. Just need the right size hole saw (diamond coated)
Click to expand...

Have the diamond saw (came with the box), but still a bit concerned about it. And it's the height of the weir that matters, not the height of the drain, correct?

And also is there a way to cap a hole in a tank? Given the position of the first hole I don't think that'll be serviceable.
 
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IOnceWasLegend said:
Have the diamond saw (came with the box), but still a bit concerned about it. And it's the height of the weir that matters, not the height of the drain, correct?

And also is there a way to cap a hole in a tank? Given the position of the first hole I don't think that'll be serviceable.
Click to expand...
You can put a bulkhead with a cap or plug in the existing hole, or use it for a return, or patch it.
 
So i wouldn't cut away the rim... serves a purpose... like keeping the tank together... :)

An option might be to put a shim to have the weir sit flush to the edge of the rim..

Alternatively, they sell overflow box/ weirs on Ebay. Switch plays and grab one of those.
 
Wlachnit said:
Yeah, you can patch it with a piece of glass using silicone sealant.
Click to expand...

Yes, be sure that the patch is on the INSIDE of the tank so that water pressure pushes it towards the tank wall and NOT OUTSIDE so water pressure pushes it off the glass wall. Maybe this is obvious, but I'm going to say it here anyway so you at least thing about it.


Acrylic might work too BUT in my experience, glass and silicone work really well, in fact that's how your tank is built Acrylic and silicone is not that great.I tried using silicone make acrylic baffles in a glass sump. It didn't hold.

V
 
This is what I would do. Measure the thickness of the rim. Get two pieces of larger than the hole (ideally the same size as the overflow box, minus the height of the plastic rim. Then drill holes in the piece of glass to match the size of the hole. Use silicon to fix them to the glass, one on the inside, one on the outside. This would shim the two sides of the overflow box outwards past the plastic rim. Run the bulkhead through the three thicknesses of glass. The bulkhead looks like it has a fair amount of depth, but measure of course.

So say your tank glass is 3 mm thick, and the plastic rim sticks into the tank 5mm and sticks out of the tank 3 mm. If you bought two pieces of 5mm glass, and drilled a hole in it and sandwiched the tank glass, you'd have your overflow inside box +5mm inside piece + 3mm tank glass+ 5mm outside piece, then outside overflow box.Make sense? Acrylic would work in this case since you're using it as a shim, and the silicon should prevent leaks,plus the bulkhead will keep the shims compressed to the glass.

That's what I'd do IF the bulkhead is long enough to allow the extra thickness.

V
 
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