professional knowledge/help required regards tank build strength

[chrismaher1505]

Hi Guys and girls

im new to the forum and returning o the hobby of which ive been out of for a number of years due to the birth of my 2 children

long story short i used tto run a fish house in my garage and had some lovely big tanks running!, i used to breed various species of central and south american cichlids.

i have recently undertaken a project to self build 2 bespoke angles tanks to fit either side of my chimney breast in my living room. the idea being to just have 2 really attractive show tanks.

but here lies he problem! i will be the first to admit i have been a bit hasty and have not done enough homework into glass thicknesses for specific tank dimensions! and now believe i may be under spec for the two tanks i have already put together that being after using various online calculators

as mentioned the tanks are a strange shape so are not the easiest to calculate

ia lot of the calculators im using are assuming the tank is rimless which it isnt as i have braced them quite thourougly (im hoping this bracing will increase the tensile strength of the panels ?

please see images attached of the tanks, one has all relevant dimensions as mentioned glass thickness is 8mm i have used a double base 2 x 8mm and have braced as shown

any and all comments and advice is welcome

[chrismaher1505]

heres a screen shot of one of the calculators (an app i downloaded) please note ive used 520 as the with as that will be the average width as if the tank volume was rectangular

[plankton]

Welcome to the forum.
I believe normal rectangular 4' tanks are usually 6mm with 10mm base, so yours sound ok.
I'm no expert though.
The only true way (in my mind) is to fill them for a few weeks and see if there's any stress, preferably in a shed or garage.

[jammedfool]

Welcome to the forum!

I have no expertise in this whatsoever, but just undertook a (smaller) self build project myself using perspex.
Just wanted to say these look amazing and looking forward to seeing them filled. That's going to look great!

As plankton said, I tested mine by filling it with water and checking for leaks/movement. I trusted my work so much I left it on the draining board.
Water volume of mine is only about 20L though, rather than your ~963L if i calculated right?

[chrismaher1505]

Welcome to the forum!

I have no expertise in this whatsoever, but just undertook a (smaller) self build project myself using perspex.
Just wanted to say these look amazing and looking forward to seeing them filled. That's going to look great!

As plankton said, I tested mine by filling it with water and checking for leaks/movement. I trusted my work so much I left it on the draining board.
Water volume of mine is only about 20L though, rather than your ~963L if i calculated right?

thanks!

assuming they are capable fully filled the volume calculations would be to the pic below, i know they are obviously not rectangular but by using the width in the centre should give me an averages to what the tank would be if it was rectangular (or at least thats how i see it in my head, pretty sure the math stacks up )

[jammedfool]

I think your length is 109cm, height 170cm, and average of width 52cm... wait... I see what i have done, the height is 700 not 1700!
Still, they are nice sized tanks for sure!
What are you planning on keeping?

[chrismaher1505]

I think your length is 109cm, height 170cm, and average of width 52cm... wait... I see what i have done, the height is 700 not 1700!
Still, they are nice sized tanks for sure!
What are you planning on keeping?

Havnt got that far yet!l lol once im happy that my front rooms not going to become a walk in swimming pool ill get round to stocking ideas

early thoughts are 1 being a planted community tank (millions of neons, corys etc maybe a couple angels while the other being maybe a single specimen/pair cichlid species (haitiensis are my favourite fish ever!) but unfortunately fully grown would be too big for a tank this size

[fr499y]

They should be fine. I would of put the braces lower in the tank ( not by much, just so they are under the front/rear pane ) As said, most 4ft tanks are 6mm or 8mm. IIRC juwel 4ft tanks are 8mm with a plastic central brace bar.

[chrismaher1505]

They should be fine. I would of put the braces lower in the tank ( not by much, just so they are under the front/rear pane ) As said, most 4ft tanks are 6mm or 8mm. IIRC juwel 4ft tanks are 8mm with a plastic central brace bar.

I think the length and widths are not the real issue it is more the height by all accounts as the calculaters I've used increase the glass thickness dramatically from 500 tall to 700 tall.

But also Its difficult to get a really good answer from these calculations as I believe they are only allowing for rimless tanks ie no bracing what so ever.

I'm trying to get an idea how much stronger and fit for purpose the tank is as its braced even though the glass thickness may not be as thick as preferable

[fr499y]

Tank Water Height (H) (mm): 700
Tank Length (L) (mm): 1150
Tank Width (W) (mm): 700
Recommended Safety factor (Sf) : 3.8

Recommended Side Glass Thickness at Sf: 13.3
Maximum Deflection of Glass (mm): 0.44

Recommended Bottom Glass Thickness at Sf : 18.7
Maximum Deflection of Glass (mm): 0.34


So working on that theory, 15mm glass with a 20mm base is what you need for a braceless tank, knock a couple mm off the thickness for a braced tank and 10mm is probs more where you would want it. I suspect the water pressure to increase by quite a bit from 400mm to 700mm height. You might get away with it at 8mm, fill it up outside ( or garage or a place it can drain properly! ) stick a pump in and leave it a few days and see.