a 500g one glass sided tank ..

[zazz]

Silicone WILL NOT adhere to plexiglas or acrylic with enough strength to be used for structural purposes.

I concur with the reccomendations that say that plywood/glass construction and a framed tank support would be a better approach. If you were aiming for an 800+ gallon tank size, I would modify that reccomendation to welded steel and acrylic construction. But with either glass or acrylic, the water pressure is used to force the glass/acrylic against a resilient seal on the the inside of the frame of the viewing window.

You were not explicit about the floor construction, but I have experience with reinforcing underneath wooden floors with telescoping steel columns that incorporate adjustable screw jacks. This is preferable IMHO since you will likely not own the property your entire life and demolition of a concrete tank will be expensive.

The floor reinfocement is quite simple. Two columns would be used, one at each end of the tank, and on top of these in full contact with all the floor joists is a longtudinal beam (steel or wood) that is in contact with all the floor joists above. The lower end of the columns rest upon a concrete slab. The columns are adjusted util they press lightly against the floor joists and prevent them from deflecting downwards from the weight of tank and water.

thanks but its acctually a ground floor concrete slab.

inspirational shot....

maybe i shouldnt post that last shot because everyone will think i am putting it on the floor level!!

but just to recap silicone bonds well with concrete ..so there is no reason why i couldnt treat the frontglass the same way as an 11ft convetional tank with bracing at the top??

 

[frootloops]

Hey Zazz, I also made a tank using concrete and glass. Looking back, I should have gone with wood. Sure concrete is stronger but now I constantly fear that when an earthquake happens, cracks will show up everywhere and water would gush out of the tank. I also made use of existing walls to serve as the walls of the tank. Difference is, rebar was added to those walls and another layer of concrete was poured to make the walls stronger as water is very heavy. To mount the glass, just make a concrete frame where the glass will sit and apply lots and lots of silicone.
If I had to do it all over again, I would use wood or stainless steel instead of concrete. Concrete is permanent and if you were to move to a different house you have to leave your old tank and make a new one.
A lot of waterproofing material was used in my tank. Rubber mats were installed all around the tank sandwiched between the concrete. Flexseal, and Thoroseal was also used. I filled it up and it still leaked. Just minor leaks though. I bought some more Thoroseal and used Castle primer and paint for the topcoat (Castle is very flexible so hopefully if the concrete underneath cracks, the Castle layer won't crack). All in all I used almost all 3 cans of Thoroseal and 2 and 1/2 cans of the 4kg tub of Castle. Hopefully it won't leak anymore . Going to test it on sunday.
By the way, what method did they use to waterproof the aquariums in Manila Ocean Park?

 

[zazz]

after much research the design falls down in one area.. and that is the 11ft glass. Im sure deep pockets could make it happen ..but for now that project has been canned.

However i am going for an 8x2.5x2 ft 300 gallon conventional tank on a conventional stand!!

 

[Conner]

after much research the design falls down in one area.. and that is the 11ft glass. Im sure deep pockets could make it happen ..but for now that project has been canned.

However i am going for an 8x2.5x2 ft 300 gallon conventional tank on a conventional stand!!

I think if you were to pour a ledge along the front of the slab, and sides on the wall, tied in with rebar, this would be strong enough to support the glass against. Then you don't have to worry about the silicone "holding" the glass in place, the water pressure will hold the glass against the ledge, and the silicone just acts as a gasket.

If you mean you can't get an 11ft piece of glass because of funding or availability, that's an entirely different thing.

You could also put a pillar in the middle, with the top tied into the rear wall, so that you can use two smaller pieces of glass, which would be cheaper and easier to acquire...

 

[zazz]

well acctually my final soloution was along the lines of a concrete rebar lip on the bottom and the sides with a metal crossbrace on the top that was welded to the rebars either side and tied to the back concrete shelf....

but it was at that point that i realised that this soloution on paper would work but in reality it was going to be a huge cockup..im not sure where or how but after reading countless similar posts on problems i was put off.

if someone was to offer a one inch thick piece of plexiglass then it would be game on.

having said that when i am a rich guy that could well happen.... so the project is canned but not dead..officially.