# Mixed material construction/modification?



## Edwii (Jan 1, 2012)

I have this tank mod I want to attempt










How it works is the little box inside the aquarium will house the intake/outtake lines for a canister filter; they come from under the base of the aquarium and go in thur the water tight cube in the center.
The purpose of this mod is so that no wires/tubes/etc will be hanging off any side of the tank, allowing it to become a perfect center piece to be seen from any and all sides with out any hardware in direct view.

My tank is 30x12x13 (20gal)

► The *question *I have is can I construct the box out of something other then glass(lexan,plexi,acrylic,pvc,abs,other?) AND be able to get it to seal to the glass? As far as I understand an aquarium safe silicone wont make a seal to plastics against glass, there for I have two options I want to ask about:

◘ Is there a sealant/epoxy/etc I can use that will be strong enough to make a seal between a plastic material and glass and is fish safe?
◘ Is there a material I can use that will seal against the glass bottom using standard silicone? (it doesn't have to be transparent)

►Why not just make it out of glass?: Because I need holes drilled into it; 1 in the bottom of the tank, 3 or 5 in the sides of the box. To get the local glass shop to drill the holes he quoted me roughly $30 per hole($180). As long as it's not glass I can drill it myself. (unless some one know's some one who may drill it for cheaper?)

Thank you for any help and words of wisdom.


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## MEDHBSI (Sep 4, 2011)

*bad link*

Link doesn't work


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## Edwii (Jan 1, 2012)

MEDHBSI said:


> Link doesn't work


Sorry, I clicked post before i was finished editing, all fixed.


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## christhefish (Nov 8, 2010)

i would be a little worried of it imploding
what i would do is just have two holes in the bottom of the tank for pvc input and outflow i would also reinforce the holes


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## Edwii (Jan 1, 2012)

christhefish said:


> i would be a little worried of it imploding
> what i would do is just have two holes in the bottom of the tank for pvc input and outflow i would also reinforce the holes


My image does not display all the holes:
I need 2 for the filter,
1-2 for co2/air 
1 for a wire conduit to the surface for lighting.
(+1 for all the wires/tubes to go thru the bottom)
Drilling that many holes directly into the bottom of the tank would probably be worse I would think and still just as expensive. I can always brace the inner walls of the cube to help prevent imploding.


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## Rastapus (Apr 21, 2010)

Good idea, not safe. Any leak will result in the entire aquarium draining. Better to have a PVC inlet and outlet and closer to the surface of the aquarium. What if the canister leaked? Very bad.
If you want to pursue this, yes the box would have to be glass as well, bonding plexi or other material to glass generally does not work. Although it is true that overflows are done in this way, if there is a leak the aquarium would still function and not cause a leak by design and the drain is at the top minimizing serious accidents.


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## christhefish (Nov 8, 2010)

oh ok i think i understand it should look nice if you could pull it off
i'll keep thinking


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## christhefish (Nov 8, 2010)

i cant think of a way to do it with a glass tank
if it was an acrylic tank i think it could be done
this is going to bug me lol


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## Edwii (Jan 1, 2012)

Rastapus said:


> ►What if the canister leaked?
> ►Although it is true that overflows are done in this way, if there is a leak the aquarium would still function and not cause a leak by design and the drain is at the top minimizing serious accidents.


►I was planning on installing shut off valves to the lines going to the canister, if that's what you mean?
►I haven't been at this very long, What is the difference between my concept and and Overflow?


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## Edwii (Jan 1, 2012)

(double post)


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## Dietmar (Dec 15, 2011)

The overflow in the pic is open to the top. The pipes going through the bottom of the aquarium go through bulkheads that are sealed to the glass and the pipes go all the way to the top. There will be only 2 or 3 holes. The black overflow itself does not have to have a perfect seal.
As I understand it you are going to bring wires in as well? How will you seal those?
In your design, you will have many holes in a small area which will be in the bottom of the tank, where the most pressure is. And the holes will be close to the edge of the "box". I am not certain on the rule, but there is a minimum distance holes should be to an edge. And a certain distance the holes should be from each other. Hopefully someone more qualified can answer this.
At any rate, email a tank builder, they should know.


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## Edwii (Jan 1, 2012)

Dietmar said:


> ►As I understand it you are going to bring wires in as well? How will you seal those?
> In your design, you will have many holes in a small area which will be in the bottom of the tank, where the most pressure is. And the holes will be close to the edge of the "box".
> ► I am not certain on the rule, but there is a minimum distance holes should be to an edge. And a certain distance the holes should be from each other. Hopefully someone more qualified can answer this.
> At any rate, email a tank builder, they should know.


The top of the cube would be a hole/bulkhead fitting big enough to fit a wire thru then simply attach a pipe via the bulk head fitting that goes thru the top. just like the other holes each will have a bulk head fitting, except the main 2" hold in the bottom of the tank itself.

The bare minimum amount of holes needed:
◘ 2x 1.5" holes at opposite ends of the cube for the intake/outtake bulkhead fittings for the filter
◘ 1x 1.5" hole for the bulkhead at the top in which would fit the electric wire and a possibly a co2 tube.
◘ 1x 2" hole in the bottom to allow any and all tubes/wires to go thru the bottom.
Summery: 4 holes total, and only 1 hole per side of glass being used.

►Any one here a tank builder?


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## gklaw (May 31, 2010)

Looks a bit too complicated for what you are trying to achieve. All you need is:

- one bulkhead of intake raised with pipe to whatever level you wants
- one bulbhead for return

Heating - use inline heater 
CO2 injection with atomizer (check with Mykiss)

The only technical issue you may have with this design is to control the pattern of the intake - too much flow and you could be creating a vortex. I never tried this arrangement before, just some observation and I think someone on the forum has done similar in/out, albeit not right at the bottom of the tank.


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