New large Tank Concerns

[BigDaddyD79]

If someone could help with feedback that would be most appreciated. So, I've upgraded from a 55-gal freshwater tank to a 160-gal tank. I have a big concern because the 55-gal tank has braced the surrounds the tank at the bottom and top. The 160-gal doesn't have any brace to help support holding the panels together. the walls are much thicker compared to the 55gal almost 3x thicker on side walls and 4 times on front back and bottom. The tank is made out of some kind of Plexi glass not real glass. So, I'm a little worried the thing will blow apart with the weight of the water. I don't know that much about tanks.

[Andy Sager]

Originally Posted by BigDaddyD79

If someone could help with feedback that would be most appreciated. So, I've upgraded from a 55-gal freshwater tank to a 160-gal tank. I have a big concern because the 55-gal tank has braced the surrounds the tank at the bottom and top. The 160-gal doesn't have any brace to help support holding the panels together. the walls are much thicker compared to the 55gal almost 3x thicker on side walls and 4 times on front back and bottom. The tank is made out of some kind of Plexi glass not real glass. So, I'm a little worried the thing will blow apart with the weight of the water. I don't know that much about tanks.

Plexiglass tanks are different than glass tanks in that the agent that bonds the different panels together actually melts the plexi into each other forming a single piece vs silicone which just holds the 2 separate glass pieces together. I'm surprised there are no braces in the center or along the top to stop any bowing tho. Can you post a pic from above the tank looking down so I can see the construction?

[LVstealth]

is it cast acrylic? not sure why the pieces are different thicknesses, but if my math is right it would be somewhere in the neighborhood of a half inch thick. the cast acrylic can stand the pressure for a long time (years). the glass has the brace because of how glass is. for the acrylics it is pretty straight forward math, but glass has lots more factors to consider.


if it were just a strength thing, the cell cast acrylic would be the way to go.



i played with acrylics (not in aquariums, just for work) for a few years. lots of advantage to it.



im waiting on Alon (transparent aluminum) technology to get cheaper. right now it would be a $100,000 to try and build one (if they could get the tech to build big). just a dream though.



have you decided what to put in it?

[BigDaddyD79]

I was thinking of putting a devider in it so that i could have i beleive they call them community and school fish and I think I might use my 55gal and start a salt water tank

[LVstealth]

i would have to get a bigger house for that! im envious!

[BigDaddyD79]

It is one heavy son of a ***** too

[Andy Sager]

Originally Posted by BigDaddyD79

It is one heavy son of a ***** too

Yeah it's amazing how heavy a well constructed tank can be.
I see a border around the top so I wouldn't be too concerned about bowing. With thinner plexi, a simple 1" wide strip glued to the entire top of the tank ( inside not on the actual top) stops the acrylic from bowing as it does with glass.
I would suggest, for your own piece of mind, place something 1/2" longer than the width of the tank on top of the tank as you are filling it so you will see if there is any bowing and how much if it is. I use a 1/2" extra so that if that falls into the tank while filling, STOP FILLING!! and address the issue with the manufacturer.

[BigDaddyD79]

So I filled the tank up a few days ago and noticed today its starting to bow front and back any suggestions?

[Aiken Drum]

How much is it bowing?

[BigDaddyD79]

Originally Posted by Aiken Drum

How much is it bowing?

right now if i hold a level at the center the level will teeter tot .5in

[Andy Sager]

Is it bowing at the top of the tank or in the middle of the panes?

[BigDaddyD79]

Half an inch from center. I emptied 5/8 of the water in the tsnk didnt want it geting bigger

[Andy Sager]

Originally Posted by BigDaddyD79

Half an inch from center. I emptied 5/8 of the water in the tsnk didnt want it geting bigger

It sounds like the acrylic has lost it's integrity which is why it is bowing like a belly even tho it is thick acrylic. A tank your size should be using 3/4" plexi. If this is a new tank, I'd be talking to whoever you have a warranty with and get the tank replaced. If it is a used tank, the tank's age may be why they were getting rid of it.
Possible solutions would be to glue in a top to bottom divider ( use "weld-on" acrylic cement) in the center of the tank which will give you some extra support against the current bowing but it will have no effect on future bowing and I would think that other spots in the panes will eventually weaken and bow as well.

Personally, I wouldn't trust the tank due to this.


EDIT: This is where I got my info from ( https://www.learntheaquarium.com/acrylic-aquariums/ ) but I misspoke that it should be 3/4" because this states a minimum of 1/2". That said, with a large tank, I wouldn't be doing minimums.

[Colin_T]

They normally use thicker glass/ Perspex on tanks without supports. That adds to the weight and cost.


The tank should not bow anywhere, especially 1/2 inch.


If you bought it new, you could return it and get one that has cross members and support straps. Alternatively, glue some cross members to it to help stop it bowing outwards.

[BigDaddyD79]

1/2 inch

[BigDaddyD79]

It was used. Any idea how long the pleci will hold it strength for. I would think it would have already been bowed when I picked it up. Ill contact him for more info as far as how long he had it what it was used for. the acry cement can this be done just by lowering the water level lower or do I have to completely drain?

[BigDaddyD79]

the weldon arcylic cement has a bunch of different ones. the all have a # asigned to the type of cement it is any idea the # that would be best?

[Andy Sager]

Originally Posted by BigDaddyD79

It was used. Any idea how long the pleci will hold it strength for. I would think it would have already been bowed when I picked it up. Ill contact him for more info as far as how long he had it what it was used for. the acry cement can this be done just by lowering the water level lower or do I have to completely drain?

Sadly, there's no real way of telling for sure but in reality, the integrity is already compromised so how long do you want to chance it getting worse? I'm less concerned about the panels separating as I am the plexi stretching to the point of bubbling and then breaking.

As for the weld-on, I use either #4 or #16. The #4 is a liquid while the #16 is more of a gel. You'd need a dispenser bottle to apply the #4 so that you get the liquid in the proper space while the gel can be directly applied from the tube. There are many Youtube videos about welding plexi you should look at before deciding to do this.

[Colin_T]

If you glue a support strip on top you should drain all the water out, or at least most of it. A couple of inches in the bottom is fine but you want the water level as low as possible when gluing the strip on.


If the tank was set up for a while and it never had support straps, it might be fine. Check the seams where the panels meet and see if there are any bubbles or cracks in them. If there aren't, you should be good to go.