Few questions on building a 4' cube tank

[Arthur]

Well I have 2 40 gallons that I got for free, one of which had a broken side, and I don't really need to have the other in use. So I'm thinking about using the 2 tanks to make a 4 foot cube tank. With the 2 40's the tank will only be 17" tall, but that'll be alright since it's going to be for my turtle.

I checked out the tank builder on GARF and it said that I'd be fine with 1/4" glass which is what the 40's are made out of, but I think I'd feel safer with a 3/8 bottom, which I priced out at around $120-130.

I wanted to seek advice on if the 3/8" bottom would be sufficient first of all. Secondly I plan on building the tank on top of the bottom, and was kind of curious if it would be wise to get the bottom slightly larger that what I want, like an 1/8" extra, just in case the cuts were shorter than what I need.

 

[Egon]

I'm planning the same thing with 6' tanks. I have one now with the bottom broken out and I just need one more cheep 125 from CL to get started. I've done this before so this is what I learned.

yes 3/8" bottom will work for your tank.

The cuts will be exact, the glass guys are very very good at this. No need to cut larger.

You may want to look up "euro bracing" for the top. Maybe not necessary for your tank because your not filling it up all the way. When I euro braced my tank I used 3" wide 1/4 inch thick strips going around the perimeter of the 1/2" glass tank. The first layer of glass sat right on top of the 1/2" glass upper edge of the tank and went all the way around (hard to explain). I let the silicon dry for a day and then I put another 3" strip around underneath the first layer and on the inside perimeter of the tank, so these pieces are 1" shorter (the inside of the tank is 1" smaller than the outside). The tank is solid as a rock! There is no way the seams will rip out if the tank is filled all the way!

I can take some pictures of the euro bracing if my explanation is fuzzy

 

[Arthur]

Thanks for the info. I was planning on euro bracing with 1/4" as well and using 3" around the outside with a 6" center brace.

I have a general idea of how I want to brace the top, but I'd be interested in seeing how you've done your tank

 

[nolapete]

Two things:

While 3/8" glass should be fine for the bottom, I would do something to protect it on a 4' span. Any tiny rock or anything else that gets under it when moving the tank or ding against something would be a disaster.

Corner bracing would be much stronger and use less glass than center braces. You could use 4 pieces of 3" glass that connect at 1' points. With corner bracing each side pulls against the other and prevents it from moving. To accomplish that with center bracing, you'd have to have two 4' pieces of whatever size glass you decide to use.

Here's a drawing. The left lower corner shows what I was originally talking about, but you could just use triangles like in the other three corners.

 

[Egon]

Yeah, that's a good idea!

I made my tank with a 3" perimeter all the way around the top to avoid the center bracing. I think the corner bracing would be just as affective, maybe slightly less for the bowing in the middle but nothing to worry about.

I will take pictures of mine as soon as I get home from work.

 

[Arthur]

Nolapete, you make a very good point and the corner brace would be a lot more cost effective. The only thing with that design is that covers for it might be more of a pain in the butt. I think I may use a hybrid of the two though.

I'm using this tank for a "temp" tank for my 10-11" shell snapper until I'm done with school, so covers are of great importance. The funny thing is I'm more worried about my cat getting in than my turtle getting out.

I took apart one of the tanks I was going to use for the build and the bottom had been replaced so I'm going to have to buy more glass than originally planned. I now have a 16" tall tank minus a side, a fully operational 17" tall tank, and a 18" tall tank without the front. I was hoping to use the two that I thought were 17", but I think I might step it up to 18" and not take apart a good tank.