Whats the best way to patch holes drilled in the bottom of a tank?
 

So I have a 150 gallon (48x24x30) that is drilled for the traditional corner overflow. I want to change it over to an internal coast to coast overflow so I need to decommission the two holes in the bottom of the aquarium.

Whats the best way to do this, should I put in the bulkheads and then just use a threaded plug, or should I have a glass patch cut and silicon that over the holes?

And if I go the glass route, should I go with the same thickness as the bottom of the tank, 1/2" in this case?

Any words of wisdom would be greatly appreciated.

The glass patch would be the best option IMO, chances of the bulkhead leaking would be far greater than the patch.

Buy a new tank. Ha ha.

I am sure you "can" plug them, but I personally would never fully trust the tank with plugs in the bottom. Big tank. Lots of water to drain.

i would do a glass patch and glue surface to surface and all edges of the patch. not sure what thickness you have but put it terms as this if a rock falls on it will it crack easy. if you think so then its not thick enough glass patch. other than that i seeno issues

I would fill the holes with a goodly amount of silicone before siliconing the patch on. Just don't over fill the holes as you don't want that area to bear any weight from the bottom.

Thanks for all the quick responses.

I'm probably going to go the patch route, using half inch thick glass to match the tank bottom thickness.

There is a third option but It might be a half assed way to do it, reduce the size of the overflow box and install an L-shaped coast to coast overflow, so I can use the two holes in the bottom and then only have to drill one additional hole in the back for the third drain, for a bean animal style.

so I would have a smaller corner overflow with a larger coast to coast style perched on top of it.

I like the 4th option, leave as is :mrgreen:
I don't see a huge benefit of converting a corner overflow into a coast to coast. With the return placed on the opposite side you won't have any surface skimming issues.

Leaving it as is would work, as this aquarium was a gift from my other half, but then it was also stipulated that the aquarium has to be quite enough so the room can still be a guest bedroom, so I was hoping that the increased surface area would result in a large weir and make the overflow quiter, as if i have a splashing overflow, i'm pretty sure the tank won't last long.:cry:

Personally, I'd leave it as is. If you spend some time tuning the system and getting the plumbing inside the overflow box right (herbie overflow), it should be nice and quiet.

Yeah coast to coast won't be any quieter unless you're planning a wave box or something else that will generate an actual wave but such devices are noisy alone. Standard box with a herbie will be completely silent. Sounds like you've already got two holes so you're good to go.