Tank design and glass thickness q

[Borre]

Howdy folks!

I've been looking through the stickies but didn't actually expect to find anything regarding my specific situation.

I am planning on building a couple of diamond shaped corner tanks. And there are a couple of things that might not work out as I hoped but if in luck I get this looked over by you guys and then I can make adjustments or scrap it all together.

I'm pretty new in the hobby, I've only kept fish for about 4 years and had a rocky start (luckily with native fish that I caught myself) and things are different and better nowadays. If I've learned one thing, it's that there is something new to learn every day.

Anyway, for the corner tanks I had envisioned a diamond shape, seen from above like a square but with one corner cropped in a 45 degree angle to it's adjacent planes. (I'll put up a drawing if this wasn't a good clear enough description).

The size:
Volume 75 litres.
Back walls: 50 L x 35 H cm
Side walls: 20 L x 35 H cm
Front wall: 40 L x 35 H cm
(so in practical if I'd have left the tank fully square it would have been 50x50x35 cm (LWH)

The angles, just for clarification: three 90 degree angles and two 45 degree angles at the ends of the front wall.

My biggest problem is the glass itself, I only have 4mm and 3mm 20 year old window glass. With one of the glass thickness calculators in one of the stickies I got a safety factor of something around 3.5 with the 4mm glass (I had to cheat in the calculator and enter a rectangular tank with the same volume).

But is this still advisable with 4mm window glass? I have no idea of what quality it is, but it's not any more brittle than any other normal glass (I've built a huge terrarium with it also).

What can I build out of the 3mm glass? Anything at all?

The 45 degree angles worry me. Can they be made safe without the use of braces, will they hold under normal use or should all angles of a good tank always be 90 degrees for some reason?

Thanks!

 

[tuffy_rana]

i dont see any problem with this idea, tho personally i would use 6mm to be sure. the tanks not a large volume so it shouldnt cause any issues with pressure. use a good quality silicone and you should be fine imo. 3mm is only good for lids on small tanks or for betta tanks


edit: should of added that i have 3 120cm x 50cm x 35 cm fry tanks made outta 4mm that i picked up at a market cheap. filling them scared me at first....but they are still holding water at 80%full and have been for 12 months.

 

[Borre]

...

Thanks!
I've been thinking - to stretch my 4mm glass as far as possible (I want to make 3 such tanks in total but not sure if I have enough material), could I use 3mm for the bottom if I am careful if/when I place rocks in the tank?

I absolutely want to use some of the 3mm for the lid, if I can make both lid and bottom 3mm then I get the largest areas covered (no pun intended) and can use the 4mm for the sides only.

For silicone I'm thinking standard aquarium silicone. I've also been thinking of skirting the bottom and top edge. By that I mean that I'd silicone aluminium L profile along the bottom (though the segments of AL not interconnected by welds or similar, so it wouldn't be a frame in a traditional sense) and would do the same on top, just to get something to put the lid onto.

I will have to look into the practicalities of the building itself (how to organize the panes) but I'm sure there are thousands of guides out there.

 

[tuffy_rana]

wouldnt suggest 3mm for the bottoms. tho it is only 75 litres. i just think 3mm is a little too thin imo. i like that your trying to use available glass but i would just go and purchase a little more 4mm. its pretty cheap here in oz not sure on sweden but. i pick up 6mm sheets around briz for $30 odd dollars for a 6' x 4' sheet and comfortably get a 120 x 50 x 35 cm tank less lids which i make outta 3mm

 

[Borre]

i pick up 6mm sheets around briz for $30 odd dollars for a 6' x 4' sheet

I just made a quick call to the local glass place and it seems I'd be cheaper off flying half way across the world to get my glass.

For a sheet smaller than yours (6mm) I'd pay $300 Aus! For 4mm I pay $150.
That I'm currently dirt poor doesn't help.

An alternative for me might be to get a hold of used tanks and recut the glass if I need to go thicker than 4mm and need a different design than the tank comes in.

My dream is to eventually build a 375L tank which would need 9mm glass (at the least), seems I have to rob a bank in order to be able. However, I might get away with a lower punishment if I just steal their safety glass

 

[Borre]

To anyone who's still looking, a little update!

I was to my local pet store (where I end up at least once a week you could say) and had a little talk about building my tanks.

The owner didn't think either that 4mm would be too thin for my plans. He also suggested that if I used Styrofoam under the tank I should be able to go with 3mm there. And if I'm unsure I could go with two 3mm pieces for the bottom, though he hadn't tested that sort of thing and wouldn't promise that that would work 100% if something out of the ordinary happened. I could also use 3mm for the short side panes, and of course for the lid, he concluded.

Anyway, you gotta be lucky some times!! After our talk he hatched an idea. He told me that he had a load of large pieces of high quality 6mm and upwards aquarium glass at home, plus one 150L tank with a busted side, and if only he'd get a little time to think it over I could probably have all of that for free!!

From his description of what he had at home it souned as if I'd have to pay *easily* something in the order of $3000 for all that glass if I bought it at the local glass shop ($300 with Australian glass prices as it seems)! I hope he pulls it through! That would make my year! And next year too!

I have no idea where to put it, my place is filled to the brim with aquariums and terrariums, but I don't care. Just gimme me the glass, gimme!

 

[Pharaoh]

Sounds like a good deal on the glass. Just be wary of it being tempered. If it is, then you cannot cut it.

 

[Borre]

Sounds like a good deal on the glass. Just be wary of it being tempered. If it is, then you cannot cut it.

Thanks for the warning! I'll have to look up what that really means (language barrier) and how to spot it.

 

[Borre]

Sounds like a good deal on the glass. Just be wary of it being tempered. If it is, then you cannot cut it.

(No way to edit posts for updates or have I overlooked a button?)

Okay, I know now. Does tempered glass break as soon as one presses down the cutter or does it break during the process of "knocking the cut" (what ever that's called?) or during the actual breaking of the cut?

 

[dawnmarie]

Tempered glass is heat treated after cutting or drilling and can not be altered.
Any attempt to cut or drill and it will shatter.