Do i need two pieces of glass for the bottom of my tank?

Hi all,
So my dilemma, i have built my own aquarium (1500mm x 800mm deep and 550mm high), 12mm thick glass.
I have drilled 4 x 50mm holes drilled in the corners for filtration. I have done bracing on the top and the bottom of the tank, pics below.
My question, do i need two layers of glass on the bottom or will one do? I will be going on a metal stand with 20mm styrofoam and possibly a piece of marine plywood. Do you think another layer of glass is needed for support?
Sorry for the poor quality pics, it was night time.
.

 

IMO go with two layers at the bottom on that size

 

Will a piece of wood not give the same sort of support? Not as strong i know but not strong enough like that?

 

IF you have a proper stand. That being you have at least 4 support rails crossing your steel frame and that your tank would not be standing only on the outer frame of the stand alone. I would go for 25mm styro and the plywood. Plywood going on to the frame and then the styro. With this config your tank will work 100% for many loving years to come.

 

Very nice tank so by the by ...

 

If Pet Stop SA built this aquarium for a customer We would have insisted on a double bottom on that depth
PLUS
My experience with wood under a aquarium was 90% BAD -

My reasoning (M2C) are due to the following:
1. wood, steel and glass move/expand with temperature variations and the difference between wood and glass create stress on the glass
2. wood expand when wet, thus creating uneven pressure, again stress.

Enjoy this project, I am always more proud of a project if I did part of it myself

 

Thanks, it is fun building my own tank and a fun way to get into the hobby. It was a lot of work and still more to do but it's worth it.

I understand the whole wood when wet expands, i will try treat the wood to seal it so it won't expand. I have got mixed opinions on this. People say if done properly the plywood should be fine (granted it is treated properly and the tank is 100% level.) I have not built the aquarium very high as it is only 550mm high, i know i could have got away with 10mm, i thought adding the extra 12mm to the bottom would support the tank adequately.

So far i have had heaps of fun and wow is it hard work. But seeing my own project is always a plus, next time i buy it though

 

My mistake - read deep and automatically assumed that is hight - sorry !!!
One bottom is more than sufficient.

 

Lol, no worries, i agree if it was 800 high i would need 2 pieces on the glass on the bottom.
Cool beans, thanks for the info.

Floating base? Sorry not quite sure what that means.

@Moolis, so just to confirm, will i need the wood or will the polystyrene under the base work?
Thanks all for the advise

 

An normal base is where the side panels of glass rest on the top of the bottom sheet of glass. A floating base is where the side panels are glued to the outside edge of the bottom pane so that the bottom pane of glass seems like an insert into the side panels.

 

Oh ok, thanks for clarifying, then i have normal base and styrofoam base it is! :bigsmile:

 

ALWAYS polystyrene or alternative replacement product for them between stand and glass. Never have I had long term success with glass directly on the stand

An expensive alternative we use with A grade installations are a special type of sponge/rubber that can smooth out any imperfections or time related stress points. BUT this does look great, even @ 10 to 20 x the price of polystyrene.

 

+1 and if u can use special polystyrene as it can hold beter up to the tank and will last longer aswell

 

@rednox - when you say 'special' polystyrene or sponge/rubber where does one get this and what is it?. Is the polystyrene you refer to that different from 'normal' stuff ?. I like the idea of the sponge/rubber mentioned by @Moolis, I hope it is black or dark in colour anyway, because I would love to use it under my one tank that is bare-bottom. I HATE the reflection that comes from the white polystyrene that I have there now - and I think the bright white bottom disturbs the fish anyway.

 

You will be fine with one pane bottom for peace of mind I would have just glued in strips in the front and rear running parallel to your glass and then also parallel to the sides joining the strips glued to the front and back all this on the bottom of course. Four square tubing pieces on the bottom of the tank as part of the stand at the very edges then at the alternating quarters that remain. Plywood as a top and your polystyrene/rubber for the bottom to rest on and Bob is your uncle.

 

u get different polystyrene and some is even made for tanks my cousins wife has a factory that works with if thats where i heard about this and of different polystyrene will see if i can find out more!

and also how about getting some

 

Thanks all for the info
@Shrimp lover - I have done that, i having bracing on the bottom and on the top. So yes it should be sturdy enough.
Cool beans, thanks people!

 

Yes it is black and I get them in any thickness and width I need. I am busy with an installation this week where we are going to use it and will send you pictures.

 

Yes it is measured in "dv" and we normally use 15dv but with larger aquariums we prefer to use 30dv