Blocking an overflow hole

[BlueDSM]

I just bought 2 tanks cheap, but they both have holes on the bottom for an overflow to a sump.

How do I block them? Can I just put silicone on the inside around the hole, and plop a small bathroom tile (new of course :p) over it? Or is there a better way?

Also, I need to know the best way to cut glass, since the glass cover is integrated onto the tank, and I need space to run a HOB power filter. I found websites, but they all do simple 1 way cuts, where I need to cut out a rectangle.

Thanks for any help.

 

[taikonaut]

Some bathroom tiles are semi-permeable, so if you pick the wrong type, you may end up with a large salt column below the tank inside the stand.

The way to block a overflow hole is to get a comparable glass or acrylic (depends on your tank's material, which in your case, is glass?), cut it to appropriate size, and use silicone or solvent cement to join them together. For example, if the bottom panel is a 3/4 in non-tempered glass, get a piece of 3/4 to one inch non-tempered glass, cut it to about twice the size of the diameter, and use silicone to glue it to the bottom. I am sure you knew it already, but put the patch on the inside of the tank, not outside.

Cutting a rectangle out takes some skill. You can bring it to a glazier shop and ask them to do it for you. If you really want to do it yourself, be prepared to sacrifice your tank, or practice your skill on a scrap glass first. Take a look at stained glass manuel, and regular glass cutting technique... it have the detailed direction to cut rectangle, half circle, etc.. Basically you do it in several small sections and finish off with sanding/grinding to get the rough cut to the shape you desired.

 

[FranklinP]

Is there a bulk head fitting in the hole? If not maybe put one there and then just cap off the bulkhead with a PVC cap, this way you have it for future expansion. Just a thought.

 

[taikonaut]

Good point, Franklin, aka "The King of DIYers"

I was not able to go with the bulkhead route for one of my tank since the bulkhead will be right on top of a cross beam of the stand...

 

[BlueDSM]

Cool!

I think I might do the bulkhead/PVC plug thing....actually, Ive been thinking of maybe hooking the overflow up and running a common sump for both tanks.

Thanks for helping

 

[DougBak]

One thing you might want to consider if you run a common sump, is taking into account the possibility of one of your return pumps stopping.

Both tanks will need to be able to hold the capacity of the overflow for both tanks, or you'll end up pumping water all over the floor.

 

[BlueDSM]

Oh...

Would it be possible to use just one big pump in the sump, and split the output into two (1 outlet for each tank), with a valve on each outlet?

Or is that going to cause problems too?

 

[taikonaut]

Yeah, you can do that. Just make sure each of the tank's overflow can handle all the flow if all the water is being pump to one tank, and nothing to the other.