Drilling Glass Tank

[carlos_fb]

I have a 60 gallon tank 48" x 15" x 18" which I plan to drill to add an overflow box. I was wondering how big the holes have to be in order to create a good flow? I also plan to add a 20 gallon tank as a sump.

 

[james734]

I'd say min of 1" bulkhead for a overflow. Which i think requires like a 1-3/4" hole if I'm not mistaken.

 

[Krish]

When you say "holes" Carlos, do you mean more than one like 1 hole?

 

[Scooterman]

Are you planning on drilling the glass up top when you will attach a custom made overflow? I would drill two holes for 1" BH's, & the drain from the sump another two in the bottom of the overflow if this is what your asking? This would depend on how big the O/F box actually is.

 

[carlos_fb]

When you say "holes" Carlos, do you mean more than one like 1 hole?

I guess I need 2, one for the drain and the other one for the return water coming from the sump, both in the overflow box. Isn't that the way they usually make it?

 

[carlos_fb]

Are you planning on drilling the glass up top when you will attach a custom made overflow? I would drill two holes for 1" BH's, & the drain from the sump another two in the bottom of the overflow if this is what your asking? This would depend on how big the O/F box actually is.

That brings another question. How big does the overflow box should be in a 48" x 15.5" x 17" tank?

 

[Krish]

Isn't that the way they usually make it?

Sometimes, but you can just do one for the drain and have the return come over the top of the tank. That way, you wouldn't have to worry about 2 holes unless you want to do it the way you described above. For the overflow, I'd personally go with 1 inch or 1 1/4 (bulkhead and plumbing size) That should easily support about 800gph unless you had planned on having more

 

[Krish]

That brings another question. How big does the overflow box should be in a 48" x 15.5" x 17" tank?

That would also depend on how much flow you want it to handle...Any ideas?

 

[Scooterman]

Sometimes, but you can just do one for the drain and have the return come over the top of the tank. That way, you wouldn't have to worry about 2 holes unless you want to do it the way you described above.

I agree with that; for a 20g sump I'd buy a good low heat submersible pump & not drill the sump if it is glass, they usually are very thin to drill in the first place. I don't know what type of over flow your thinking about, your normal corner type that goes top to bottom or something you hang off the back or maybe a coast to coast? What materials are you planning on making it glass, acrylic or plastic?

 

[Scooterman]

LOL sorry for drilling the questions, hope you don't mind.

 

[carlos_fb]

LOL sorry for drilling the questions, hope you don't mind.

LOL of course I don't mind. I plan to make it all glass and I like the idea of having 2 holes because I'm trying to avoid having things hanging behind the tank.

Here you can see a picture of what I have in mind:

http://www.vzlainusa.com/overflow.jpg

I don't know about the materials of the overflow.

Thanks for your input guys!

Carlos

 

[Krish]

The only problem I see with that is chances are you won't be able to drill the bottom because most all tanks have tempered glass bottoms. You can still do something similar though, but instead of drilling through the bottom, you'd drill through the back and use an elbow in the overflow...

 

[Scooterman]

Ahh nice, yea I'd go according to the BH's you decide to use, they take up lots of room, so let that help as a guide as to how big it will be. Two 1" BH's will require 1 7/8" hole plus you need room to tighten the big nut, I'd say go at least 4" deep & 10" wide at least. If you drill glass, I just had my 58G sump drilled for a 1" BH, he used a 2" bit I use the heavy duty BH so if your using the regular BH then I think it is 1 5/8" hole minimal. I took it to a glass shop & it cost me $10 for one hole & they polished it also, way cheaper than buying a bit, he had a special drill press with suction cups for glass to do it, way better than me trying to do the same. I also had them cut some plexi glass for the baffles I made, they were around $9 each for 12" x 17" x 1/4", which was reasonable. Oh yea as Krish said if the bottom is tempered then you need other ideas!

 

[carlos_fb]

What do you guys mean by BH? I think I'm going to take it to my local glass shop to get it drilled, I think it's safer!

My local pet store say that the smallest overflow box they can make for my tank is 5.5" deep which to me sounds like a lot! What do you think?

 

[Krish]

Here's what a bulkhead looks like. It's what the red arrow is pointing to. You put them in drilled holes to seal it up and allow you to plumb

My local pet store say that the smallest overflow box they can make for my tank is 5.5" deep which to me sounds like a lot! What do you think?

That's not too bad IMO. The "tooth" spacing and size will be most important to allow sufficient water to fall over into the overflow

 

[Krish]

I just took a few shots Carlos of some of my bulkheads on my tank. Give me a few minutes to upload them to my computer and post them

 

[Scooterman]

That sounds good, sorry about the bh issue
Check out my signature for more acronyms!

 

[Krish]

Attachment 1 shows how a bulkhead looks through a tank. I have lockline in the tank for the output flow and on the outside of the tank, I have PVC plumbing that runs to the pump. Attacment 2 shows the bottom of my overflow where you can see the bulkhead underneath

 

[carlos_fb]

Attachment 1 shows how a bulkhead looks through a tank. I have lockline in the tank for the output flow and on the outside of the tank, I have PVC plumbing that runs to the pump. Attacment 2 shows the bottom of my overflow where you can see the bulkhead underneath

Hey thank you so much for the pictures, I got the whole idea. Your setup looks awesome by the way.

 

[Krish]

Thanks and no problem My tank is getting there...I have another pump coming in this week to beef up my closed loop some more so keep an eye out for the pics hopefully before the weekend. With that extra pump added, it should give me around 4,000 gph of flow (minus whatever headloss I will have) in about a 38 gal tank