Need acryllic tank advice

[Jayjangle]

Hello all. Earlier I scored two acryllic aquariums (one 60 gal and the other 75) for a total of $20, previously owned by a skilled aquarist. Upon text filling the first [smaller] one the back end split in half, ruining the tank. I am now trying the other and it is almost full and I am wishing for the best.

Of course, now I'm a little paranoid. I read online that acrylic tanks need support along the top to keep from bowing and bending. What does this mean? Also, I did not see any cracks on the other that blew out on the back; it sort of cracked cleanly in an oval shape going along the back end of the bottom and into the mid-upper back.

Was I testing it the incorrect way (on ground filling with hose water)? Help would be great. Thanks.

Update: I filled the larger tank with water and let it sit for a couple of hours. No leaks or anything; everything looked OK. I cleaned all of the dried salt deposits and marks from it, removed the old sand and got it ready to go. Will start cycling water in it in the next week or so, but I am still weary after seeing the first tank blow like it did. Again, advice about how to prevent acrylic tanks from blowing up would be great.

 

[friscuba]

I can't imagine an acrylic tank just blowing up unless there was something wrong, either with the tank or it's stand. Is the bottom supported? I'm not sure how well an acrylic tank would do on a stand with an open top. Acrylic material is stronger than glass, but it is flexible and prone to bowing, once you put undue stress on one area I'm not sure how it would affect other parts of the tank.

Oops, just noticed the on the ground thing. It might be best to be on a flat level surface, if by ground you are meaning soil/rock/grass/etc, there's no telling what's going on as far as varying pressures.

 

[Jayjangle]

I can't imagine an acrylic tank just blowing up unless there was something wrong, either with the tank or it's stand. Is the bottom supported? I'm not sure how well an acrylic tank would do on a stand with an open top. Acrylic material is stronger than glass, but it is flexible and prone to bowing, once you put undue stress on one area I'm not sure how it would affect other parts of the tank.

Oops, just noticed the on the ground thing. It might be best to be on a flat level surface, if by ground you are meaning soil/rock/grass/etc, there's no telling what's going on as far as varying pressures.

Thanks for your response. Thinking in retrospect, I recall the seller mentioning that I would urgently need to re-seal the lid portion of the first tank, due to it being loose. I am not sure if this would affect its ability to hold several pounds of water. On the other hand, he said the larger tank I filled was "good and ready to go", so I am wondering if this was a matter of misunderstanding. If so, I hope I can provide my goldfish (and maybe a few more friends for them, since this is a 75 gal and my mom agreed to adopt my larger goldfish in a 20gal for her classroom) with a bigger and more comfortable home without needing to worry about a leak or tank burst.

Regardless, what would you suggest I use for top support? I have never dealt with a tank this large so I am a bit paranoid. The largest my dad ever owned was a 50gal saltwater aquarium when I was a child, so I feel somewhat intimidated by this matter.

As far as the ground goes that I tested it on, it was on the concrete porch directly before my front door. it seems level enough, but then again I could be wrong.

 

[friscuba]

Not familiar with a separate "top support" at all. I could see if the seal at the top was bad it could lead to issues. The top, normally sealed by solvent to the sides, supports the sides, they provide the bracing the sides need. Normally, I'd support acrylic tanks with 3/4 inch plywood under the tank, you'll see tank stands that are open and stands with solid tops, the solid tops are for acrylic tanks generally. If the back of that smaller tank is blown out, it's probably a major job to repair it, you've got to deal with solvents and probably an extra sheet of acrylic... it's cost you money and look bad most likely, be happy that you got a big tank for 20 bucks. You got a killer deal.

 

[Jayjangle]

Not familiar with a separate "top support" at all. I could see if the seal at the top was bad it could lead to issues. The top, normally sealed by solvent to the sides, supports the sides, they provide the bracing the sides need. Normally, I'd support acrylic tanks with 3/4 inch plywood under the tank, you'll see tank stands that are open and stands with solid tops, the solid tops are for acrylic tanks generally. If the back of that smaller tank is blown out, it's probably a major job to repair it, you've got to deal with solvents and probably an extra sheet of acrylic... it's cost you money and look bad most likely, be happy that you got a big tank for 20 bucks. You got a killer deal.

Indeed, I am ecstatic over having a 75 gallon tank practically in perfect shape for that price, but I always think about such things as what happened to the smaller one. May be due to my OCD...

Anyway, he did mention I would need a solvent to take care of the lid/top part, but I did not anticipate that was vital before filling it to test. Boy, was I wrong if what you say is indeed the truth. To be honest, though, I would have only been able to use one of the two tanks immediately in my current living situation, and in the end I wound up being able to use the larger one so it evens out.