View Full Version : Building a tank

02-11-2008, 02:34 AM
I'm after some advice on building a BIG tank. Figure if I'm going to do it, might as well go the whle hog.

I want it to be 300cm x 100cm x 70cm.

I've been trying to figure out the glass sizes, because I'll have to make allowances for the glass size in getting the glass cut.

I think that I"ll need 12mm (.47") or 15mm (.59"), but not sure probably the 15mm to be safer.

I've been doing a bit of research on it, and read that the braces on the sides need to be 90% of the length long and 5% of the length wide, and the cross braces should divide the tank into squares and be twice the width of the long longbraces, so figure that if I put 2 cross braces in that should divide it into 3 x 1m squares.

So if I've got my calculations right (and somebody please tell me if I haven't!thumbs2: )

Sides x 2 - 300cm x 70cm
Ends x 2 - 97cm x 70cm
Base x 1 - 297cm x 97cm
Long Longbrace x 2 - 270cm x 15cm (90% 300 x 5% 300)
Short Longbraces x 2 - 90cm x 5cm (90% 100 x 5% 100)
Cross Braces x 2 - 30cm x 99.5cm (got to leave a bit apparently for the silicone)

Sorry about the metric to all you still using imperial, but you need to catch up with the times! LOL My brain can't think in inches, if I tried that it would never work!

Going to have go at it myself (or with my father in laws help probably since he's a qualified glazier!) as I rang a couple of tank building places and it's going to cost about $5800!!!!!!!

Just got to ring some local glass places and see how much the glass will cost!

Any help or ideas (or if you think I've got a few roos loose in the top paddock!) let me know!


02-11-2008, 04:20 AM
how many litre tank are you building.... The more litres the thicker the glass needs to be....

02-11-2008, 04:44 AM
It'll hold 2100L or 554G, when I around to get prices on getting someone to make one, the all said that 12mm ( .47inch) would be the minimum, but that they would recommend 15mm (.59inch)

02-11-2008, 04:46 AM
yeah at least we used 1/2 inch on a 220 gallon...... 554 gallons is alot of water weight to exert on glass..... that's like 4500 pounds or so.....

02-11-2008, 05:32 AM
I know it's a lot of weight, 2.1 tonne! (and thanks to my trusty phone, it has all different conversion in it, that's 4629.7 pounds!
That's why I think I'll go with the 15mm, that's .59055 of in inch, so 9/16 inch (if that is how you guys do it, lol)

Found a really good article on buliding an aquarium actually, goes into great detail, and sounds like I've got my measurements pretty spot on, so the other sites that gave advice must have been pretty right!


Got a quote from one glass place, (most of them are having a fit when I say I want them 3m long! LOL) and it was $3000, nearly half what the cheapest tank building place was. (Still a heck of a lot of money though, nearly get you half way back to Hawaii jb!)
And the $5800 didn't include getting it shipped to my place either!

02-11-2008, 05:34 AM
just watch how tall you go.... the taller the tank the thicker the glass....... Make sure you have a thickness that will support your footprint weight also.... good luck!!!!!

02-11-2008, 05:49 AM
I'm going 70cm, which is about 2.3 feet or 27.5 inches. The guy at aquarium place said that he doesn't recommend more than that or it makes it too hard to clean, and the glass place said that the highest you could go with 12mm glass is 70cm, so I figured that 70cm with 15mm glass should be hunky dory!

02-11-2008, 05:50 AM
just test it outside...... I would imagine 550 gallons of water on your living room floor is not a happy experience........

02-11-2008, 06:57 AM
I don't know if I'll be able to test it outside, don't think I'll be able to move it once it's built, one of the aquarium places said that they would have to build it on site, as they wouldn't be able to move it once it was built.

I actually just rang the glass place to find out how much the 15mm glass weighs, 37.5kg/m2, so my tank will weigh (without water!) 1489.83kg or 3284.52 pounds!

02-11-2008, 07:21 AM
yeah true I didn't think of that 550 gallons is huge..... good luck I hope you get it right on the first try!!!!!

02-11-2008, 07:38 AM
So do I JB! So do I! The website I looked at gave a couple of good ways to put one together, and I rang him before (luckily it was an Australian site!)and he said that I'd need to build the stand first and build the tank on the stand, and make sure that it was a really really strong frame, with a solid bottom, not with just edges, to help distribute the weight more evenly, as all up it will be 3589.83kg, or 7914.22 pounds!
Also that it pays to build the stand with "edges" to help support the tank, make them really snug, which he said will help building the tank too.
Soooooo..... Looks like I've got a bit do so and some money to save!
Will keep everyone posted, and definately put up some pics of the building process and the end product!

02-11-2008, 03:37 PM
This sounds awesome! Keep us updated! Be sure to save enough for two, because when your done with yours you need to build me one! :thumb:

02-11-2008, 05:51 PM
are you going to put over flows on it or what? also is the tank going to be against a wall or in a corner or will it be in the middle of the room as to walk all the way around it as i would immagine with a tank that large? just curious as diy is best way to do things imo

02-11-2008, 06:45 PM
Hey thats huge!

I think you have calculated the weight wrong. for that dimensions you listed, you need at most 10 m2 of glass, you said it weights 37.5 kg/m2 so it will be 375 kg not 1500 kg! also i thought 10mm glass weights 10 kg/m2 so 15mm should be around 15 kg/m2, not sure!

here they make a tank like that with glass of at least 16mm thickness. and I think you need long and short braces for all around the tank and also 2 cross braces of 50*100 or 3 of 30*100 cm at the top on the long braces .
also to strengthen the bottom you can put 2 or 3 cross braces of 50*100 at the bottom.

another thing is that here they put all the sides and ends ON the base, not beside it. and I think thats very important. so the base should be 300*100 and sides of 300*70 and ends of 97*70 cm.

02-11-2008, 07:39 PM
diy is best way to do things imo

PMSL, sorry m8, I know where your coming from, i really do, but,,,, but,,,,
So ya made yer 2000lt tank (try and get a grip of that) and fill it with water and it shatters with the last bucket load, Unfortunatly you were stood at the side at the time and the glass slashed your legs causing you to fall to the floor in agony, you cant walk, all you can do is crawl and the blood cant clot cos there is too much water about.

This is a very serious tank and needs very serious consideration.

Seriously, if your going to do this then give the dimensions to a fish tank manufacturer. He will work out the glass thickness or use a simple chart but you should be able to claim on his insurance if all goes wrong. Glass is very odd in the fact it is very strong in compression and weak in tension and to top it off it has limited elastic limit and no plastic limit. In otherwords, it can bend but not much and when it goes, it just goes.

Unless someone on here is a glass engineer I would be very carefull.

On a lighter note, you could ask the manufacturer to calc the thickness and send you the tank flatpacked. That would be a safer bet.

02-11-2008, 07:54 PM
It would be more expensive but have you thought of going acrylic for a tank that size. It would cut down on a lot of the weight issues.


02-11-2008, 08:08 PM
I remember Tjones had made his own tank with a great wooden stand all by himself so hes not talking in the air.

anyway in above words i assumed that fraggle knows exactly how to silicone the tank and has some exp on making smaller ones. otherwise i won't recommend at all to make such a big tank. It needs a thick layer of silicone and you MUST know how to perfectly make that arc on the edges. thats the most important thing.

02-12-2008, 11:47 AM
In regard to the weight, I have no idea how I got 1500kg, brain was in overdrive I think, LOL!
The guy that I spoke to on the phone from the glass place, gave me the weight of the glass blu-ray, the specific gravity of glass was 2.52, so if you multiply the length 100cm x width 100cm x depth 1.5cm x specific gravity 2.52 gives you a weight of 37800 grams per metre2, so divide that by 100 to give you kg, (see isn't metric easier!) that gives you 37.8kg/m2. It was also him ( and the aquarium place that was going to cost $5800 to build it) that said to use 15mm glass.

I know that this is a HUGE job, I've built a couple of smaller tanks before (and my father in law is a qualified glazier too which will help!) and the basics should be the same.
I've looked at a couple of the big tanks here, and they are built around the base, so I don't know about that, and in regards to the cross braces, I was thinking after looking at it today, that I might go with the 3, and I rang the guy at the glass place, (who's link it is to building the aquariums) he said that technically I only needed the 2 braces as that divided the tank ito even squares, (2 braces on 3m tank, divides it into 3 1m squares), but that he would probably go with the 3 at 30cm on a tank that size too, so that's what I'll do, he didn't say anything about putting cross braces on the bottom.
He said that I could email him with any questions or anything, so I'll do that, and give him all my dimensions etc, see what he says, I'd get him to build it because he sounds really nice and knows what he's talking about, problem is he's 2700km or 1677 miles away, so bit impractical!
(I don't know what PMSL is sorry Colin! *sheepish grin*)
So if I work out the correct dimensions (which I'll get the glass/aquarium guy to check), I will get it flat packed, but from a local glass company, they'll deliver it here, I'm not cutting it! It will be all cut to the specs, and the ends all polished, so no different to it coming from the aquarium company, just doesn't have to come 200km, or 124 miles, and then they'll charge to go back too, so 400km 248miles!
Our insurance company has said that the fish tanks and it's contents (apart from the fish) are all claimable on insurance if they break or something happens to them anyway, I specifically asked about them when I got the 2 I've got now, and asked then if I get a bigger one and they just said that if it breaks, it goes under accidental breakage and it cost me $100 excess! Yipee!

If I build this one and it works ZCciVic22, I'll gladly build you one, just don't know how to get it from Australia to Pittsburgh! LOL

I don't know what you mean by overflows TJones, so not sure, but yes i want it in the middle of the room, make it a real feature! (with the cost of it, it certainly better be a feature LOL)

I hadn't thought about acrylic Sailor, hadn't even crossed my mind.
I have had absolutely no experience with acrylic, has anybody out there? Is it better than the glass?

Still a while off this tank, got to get the $$$ for it first, and with a baby due in June, I'll be out of action for a while anyway, sorry if I made anybody think it was coming soon! Just got a bee in my bonnet about it the other day and had to try to work it all out.

Cheers everyone!

02-12-2008, 01:15 PM

You clearly know what your doing,
father in law a glazier :thumb:
Talking to manufacturers :thumb:
Built smaller ones and had first hand experience :thumb:
Insurance company contacted and cover confirmed :thumb:

Had a look at your maths, looks ok, a little unorthodox with this cm thing, I only work in mm or m, but your clearly on the right path.

PMSL=Piss Myself Laughing. I wasnt having a go at Tjones or trying to abuse, its just that I nearly spat my dinner out reading that comment. I would congratulate anyone attempting to build a tank themselves but this baby is the mother of all tanks.

Seriously, we need pictures, step by step building pics if you can.

Best of luck

02-12-2008, 10:35 PM
LOL, I really am putting a lot of thought into this mate, really I am, I work in mm too, the only reason that I put it in cm was that the converter on the site uses cm, and didn't know if those who don't use metric (yet! Hopefully! lol) would know that 10mm = 1cm, that was for their benefit, in case they tried to use the converter, I hate working in cm!

I will definately be taking pics when I build it, don't worry about that! You'll be inundated with them and sick of me by the time it's done LOL.

PMSL(thanks for that:hmm3grin2orange: ), it definately is the mother of all tanks, figured go the full hog, hubby wants a big one too (actually he wants 2! He wants one for outside near the entertaining area and fill it with barrumundi and bass etc) so didn't have to do any sweet talking to get it, so thought Go for it!

As I said, it'll probably be a while off to get the $$ together, but then it will be all guns blazing!


02-12-2008, 10:54 PM
make sure your floor can stand it. its like 2.5 ton. the middle of the room usually has the minimum strenght. if you are not sure about that, consult with a structure expert.

one reason that they put sides and ends on the base here is that because this way they apply pressure on the silicone by they own weight and it gets tight enough by itself.
but if you put them around the base probably you need to force them get tight by a rim or frame.

02-12-2008, 11:53 PM
Building an extension on the house, will have a concrete slab, and will check out with the builder the weight thing, knew it was going to be heavy, the rest of the house is floor boards, so there is no way it was going to be going there! I think half the reason that I want one this big is that I was GIVEN one this big about 5 years ago, but didn't know if it leaked (had been in a shed for about 10 years, ladys son, who died, had it set up as a SW reef) and I had no where to put it, so I swapped at the LFS for the 2 55G that I've got now, ( they got the better end of the deal there, but just didn't have anywhere to put it! But apparently it leaked like a sieve too, and they had to do a lot of work to get it up to being able to be used as the display tank)
So as I said, doing lots of homework before actually going ahead with this!
Thanks for the thought though, could've easily slipped my mind in all the numbers I've got going round in my head! Build the tank, it hold water, and then falls through the floor! LOL, wonder what the insurance company would say about that!

03-03-2008, 05:18 PM
Fraggle - your proposed tank is awesome. It certainly appears you are doing your homework up front.

FWIW, to me, one of the biggest challenges you will face with this mother-of-all-tanks is proper filtration and adequate water circulation. Since the tank will be placed in an addition to the home you might consider running plumbing to the tank while you are building. That way when you do water changes the waste could go down the drain located under the tank and a faucet right next to the tank would be extremely handy. No hoses or buckets to mess up the new floor in your beautiful addition. Also, you may want to decide on what lighting you will employ prior to constructing the tank cause additional top braces might make the lighting task easier.

I suspect pretty much every design/build decision you make will impact some other aspect of the tank later on. This certainly is not a project for the faint of heart.

What do you plan to stock in it?

Best of luck,

03-07-2008, 09:39 AM
Hi Daniel!
I was considering running a bunch of big momma size cannisters off the tank, thought that would help the water circulation too. Am talking to a big LFS in Melbourne about what would be best, he's more than willing to help. Even said he would talk to the builder to let him know what I'd need! Been great.
Hadn't even thought about the plumbing situation, what a great idea!!!!! Will definatley be talking to the plumber and the sparky about the water and power, make life a whole lot easier. LOL Think about what's needed to support the tank, and don't think about how to fill this swimming pool! (might hire it out on weekends to any people wanting to practice their scuba diving, lol)

I have a few fish to stock it with, I've got an oscar, a gibby and a tandanus that will need a bigger tank, as will as a couple of silver dollars that would like a bigger tank and my sister in law has 2 more dollars in her 55G that she wants me to have too. People will probably tell me I should do a biotope of some sort and not mix fish, but they are the reason that I want the bigger tank!! We'll see how we go though, will probably add a few to that, might look a bit bare with just those! Actually, probably VERY bare! LOL, Any suggestions appreciated:ezpi_wink1:

Bald Eagle
03-20-2008, 07:41 PM
What a tank and what a project.

In regards to acrylic:

The Upside - it is about 10X stronger than glass, and much lighter.

The Downside is it scratches far more easily, and the material is generally much more expensive.

Good Luck!

03-27-2008, 07:21 PM
this tank is gonna be huge lol good luck with it!
im just curious about how much all the glass costs??.. i wanna build a tank as well but much, much, much smaller, like 100 gallons or around there..

03-27-2008, 07:36 PM
man 550 odd gallons *stares off in wonder* Lol!

Sorry i cant help with anything about making it but Good Luck!!!