Installing "ghost" type overflow

[Radman73]

I'm preparing to drill my 72x24x30 220gal tank. I have a toothless ghost type overflow from modular marine. Should I match up the top of the internal box to be at approximately the same level that the bottom of the teeth for the original corner overflows were at? In my mind, that should keep the tank water level where it was meant to be by the manufacturer.

For obvious reasons I don't want to screw this up lol!

Thanks!

 

[Hammerheadz]

I'm preparing to drill my 72x24x30 220gal tank. I have a toothless ghost type overflow from modular marine. Should I match up the top of the internal box to be at approximately the same level that the bottom of the teeth for the original corner overflows were at? In my mind, that should keep the tank water level where it was meant to be by the manufacturer.

For obvious reasons I don't want to screw this up lol!

Thanks!

That sounds correct. Top of your inside box should be same as bottom of teeth of old overflow; assuming you liked the water level at old set up.

 

[Radman73]

That sounds correct. Top of your inside box should be same as bottom of teeth of old overflow; assuming you liked the water level at old set up.

Thanks, never had the tank setup myself, just didn't want the water level too high to too low. Seemed like the right thing to do but always worth a second opinion before drill, baby, drill time!

 

[Hammerheadz]

Thanks, never had the tank setup myself, just didn't want the water level too high to too low. Seemed like the right thing to do but always worth a second opinion before drill, baby, drill time!

Good luck!

 

[Xclusive Reef]

Hey radman take some pics. I am going to drill also when my kit gets here next week or so. I too not sure where to cut the wholes? I was thinking 1.5 inches from top of tank? Sounds about right?

 

[Lazys Coral House]

i wish these new overflows would do some innovation when it comes to water height. Using sliding wier/teeth would allow the end user some adjustments based on flow rate and installation height.

 

[Radman73]

Hey radman take some pics. I am going to drill also when my kit gets here next week or so. I too not sure where to cut the wholes? I was thinking 1.5 inches from top of tank? Sounds about right?

Will do. I need to find some scrap plywood to make a template. Then I'll use a clamp to hold it in place while I drill. You'll cut the holes based off the layout of the overflow. That's why I'm making a template. I can lay the outside box over the plywood and just use a sharpie to mark both holes. Use a hole saw that's the same size as my glass saw and it can act as a guide too. Might have to make it a bit bigger to allow for water cooling.

This definitely falls into the measure 50 times and cut once category. Really don't want to trash a perfectly good tank.

 

[Xclusive Reef]

radman did you get the drilling going?

 

[Radman73]

radman did you get the drilling going?

Not yet. Too busy. Hopefully this weekend. Want to get it drilled and off the back porch.

 

[Radman73]

I "think" that the hole is far enough from the edge but it's closer than what I thought it would be before I got a template up.

Any thoughts or concerns? I was planning on putting the tank up on its end so I'd be drilling down but am worried about stress from the weight of the tank and drilling so close to the edge could cause the glass to break. May just squat in the tank and go oh so slow with the drill. I can make one of the kids hold the hose to keep the bit cool.

 

[Xclusive Reef]

on the side? i have not seen anyone drill on the side. Interested see to final product..

 

[NeverlosT]

keep in mind the old overflow had teeth, so it restricted flow somewhat and the running water level ended up being slightly above those teeth.
The new overflow without teeth will not have that restriction, and the running water level will be slightly lower if you position it at the same level as the bottom of the teeth of the old overflow.

Good luck!

 

[Radman73]

For what it's worth, the hole is 2.75 inches across and the center is 3.75 inches from the side and about 4.5 inches from the top.

 

[_Alex_]

Are you drilling a tank that previously came from manufacturer with overflow boxes?? Just quick read the thread and I thought that what It said. If so I would think the glass would be tempered and not able to be drilled.

 

[Radman73]

Are you drilling a tank that previously came from manufacturer with overflow boxes?? Just quick read the thread and I thought that what It said. If so I would think the glass would be tempered and not able to be drilled.

Yes, tank was previously drilled on the bottom by the manufacturer. The side glass is not tempered though. Honestly, don't think the bottom is either but I haven't flipped it on its side to test.

on the side? i have not seen anyone drill on the side. Interested see to final product..

Yes, layout of the room made a side overflow preferable to the back wall. I can put it on the back wall if necessary but would like to avoid that if at all possible. Back wall would make it very difficult to access the overflow and associated plumbing. From the side everything is within easy reach.

keep in mind the old overflow had teeth, so it restricted flow somewhat and the running water level ended up being slightly above those teeth.
The new overflow without teeth will not have that restriction, and the running water level will be slightly lower if you position it at the same level as the bottom of the teeth of the old overflow.

Good luck!

Thanks lol! The tank is always the cheapest part anyway right? Wouldn't be the end of the world if it broke while I was drilling. My wife would give me the what the heck were you thinking look and it would suck to dispose of the tank.

My concern is more long term. I'll use pipe supports with the idea being to put as little stress on the glass from the bulkhead as possible.

What's funny, or not, is that the bottom holes are so close to the edge the bulkhead overlaps the silicone. Bottom pane is probably thicker than the side though. Maybe lol!

 

[Xclusive Reef]

how are you closing the holes in the bottom? just gonna cap the bulkheads?

 

[Radman73]

how are you closing the holes in the bottom? just gonna cap the bulkheads?

Yep. Using thread x thread bulkheads. Will use teflon tape and a cap top and bottom.

 

[Radman73]

Discretion is the better part of valor. After reading everything I can the "gold standard" seems to be the center of the hole needs to be 1.5 times the diameter from the nearest edge. With this large of a tank, even if it drilled successfully, I'd be forever worried that the tank might fail. Or rather my modification to the tank might fail. So, it'll go on the back centered. The consolation prize is I do have room to put the tank on another wall so the entire tank is visible when entering the room. I'll make do with the limited access to the overflow and plumbing. Hope to have pictures of 2 holes in a tank later tonight or tomorrow!

 

[Radman73]

And, the deed is done. Took about 45 minutes for 2 holes through .5" glass. Not too bad. Internal overflow is a little higher than I planned but it still shouldn't be an issue. I'm not planning on having huge flow from the return anyway nor am I particularly fond of waves on the surface. To be on the safe side I may run a bead of silicone along the inside edge of the trim anyway.

Thanks to those who provided feedback!

 

[Radman73]

Oh, on a side note, gotta love my wife. First thing she asked when I told her I was going to put the tank on a different wall was "Is that going to affect the automatic water changes?" I love it when she talks dirty to me!