Open bottom aquarium glass question

Kamto

Hello All, I am new to this forum and would like to introduce my self as well as having question that has been in my mind for a while now. Please call me Kamto :o) I am not physicist so please forgive me if I am not knowing much about physics. Ok here is my question:

I am planing of making an open bottom aquarium or inverted aquarium or romaurie effect (which evername we might call it, it's the same thing) It's the same principle as if we put water in the glass about 3 quarter, and cover the top of the glass with a piece of paper, then put it up side down and the water does not fall off. In this case the glass is the aquarium. However, instead we cover the bottom of the aquarium with paper, we put the aquarium on the water surface of a pond. If you are interested, please look up on you tube or the net. There are many sites of them.

My question is: Can we use thinner glass than regular aquarium glass to build such an aquarium. If we can, is there any formula I can use. Thank you so much in advance for your help.
Kamto

A.T.

No, the pressure difference is the same. But the direction is opposite, and that might be a problem if the glass fixation to the frame is only designed to withstand higher pressure on the inside. The glass might fall out of the frame into the aquarium.

russ_watters

Could also be a problem for the "bottom" if it was intended to have external support.

Kamto

Ok :o) Thank you so much A.T and Russ_Watters for the quick replys. Yess, the top glass caved down on me, the first time I tried to pull the air out. So I reglued it back and put a glass bar (5cm x 50cm, with 6mm in thickness) in the middle of the top glass panel and it worked. It's been running for about 4 months now. However, I am planning to make a bigger one. The one I have now is 100cm long x 50cm wide x 40cm tall and all used 6 mm thick glass except for the bottom glass that support the whole aquarium.For the support the 8 mm is used. I am planning to make 200cm long x 100cm wide x 150cm tall.

Thank you for your info A.T and Russ :o) I think it's time to be working on this. :o) cheers

sophiecentaur

Did you pick up on the point that the glass should be glued to the outside of the frame and not to the inside? That could make a huge difference to the sealing properties of the joins.

Kamto

Sorry for taking me sometimes to reply. Yes sophiecentaur, I've thought about that. Thank you for assuring me. Now I just have to think of how to make it looks neat. :o)

sophiecentaur

Some extra decorative beading around the outside, perhaps.
You can expect quite a lot of bubbles at the top of this upside down aquarium. Presumably you are going to aerate the water - which will be good for the fish but not good for the bubble situation. If you could drill a hole in the top, you could remove the air through it using a syringe. Or a sort of upside down siphon could also work, once you prime it. Nice little problem for you to solve.
Enjoy.

Kamto

Thank you again sophiecentaur for yor reply.I am sorry I just write back now. Yes, I did made a hole for the air sucktion system. However, I have no idea of the " upside down siphon". Does this mean the water outside the tank is sucked into the tank?

sophiecentaur

Long time since I though t about this and I'm not exactly sure what I meant at the time. Pity you didn't challenge me at the time haha, I might have been able to justify it. I think my idea involved a long tube down to the floor (into a bucket), full of water, extending up to the highest point in the invert space with the air in it. Water should flow down this (as long as the bucket level is well below the level in the trough and, if the tube is narrow enough, it should sweep air bubbles down in with it. Perhaps even a pump could do this. It would be good it it could work without your intervention.