How much bowing is normal on an acrylic tank?

[charlypooh]

I picked up a 50 gallon acrylic tank earlier this week and filled it up with water today to see how much of the light scratching would be visible when filled. I was surprised how much the front and back panels bowed, about an inch in the front center and back center. Is this normal? The acrylic appears to be 3/8 inch throughout.

My 46 gallon bowfront is glass and doesn't do this at all...but maybe the front panel absorbs the pressure being that it's a bowfront in the first place?

 

[Peppie]

Is that 1'' just for the front? and 1'' for the back? or is it 1'' combined? 1/2'' front, 1/2'' back? I would think 1/2'' is close to normal per front and back. Depending on the age of the tank. But 1'' for just the front, and 1'' for the back would be extreme. If you have any concerns about the bowing you could easily add an euro brace.

Does it have a big bow without the water?

 

[charlypooh]

I might be exaggerating by saying a full inch... Hopefully the pics will help. The back center bows just slightly at the very top of the tank at the access point where the brace is really thin, but otherwise, there's no noticable bowing when empty.


Front


Back

 

[Peppie]

LOL You need a new tape measure. That looks typical. IMO add some rocks and some salt and get on with it

Post lot of pics

 

[charlypooh]

it'll be a while. i've got a "to do" list before switching...starting with putting together a decent stand for it being that my existing stand won't fit this tank. i just couldn't pass up the $35 deal.

 

[Burke]

How do the seams look? Any signs of stress? If yes, you could reinforce the seams. If no, set it up and just check the seams occasionally.

 

[charlypooh]

by stress, do you mean crazing? the seams are clear except for one small spot at back left where it looks like there was some bubbling when the acrylic was originally fused. any idea if that spot could be filled now?

 

[Frankie]

Looks a bit excessive to me. That tank should have been built out of 1/2" not 3/8". Looks like it will be fine though. I would expect that from 3/8". Just try to take your pictures from now on head on

Look forward to the build thread!

Frank

 

[Burke]

Yup crazing. Sounds like it's not an issue. My tanks are all 3/8" and yes they bow, but it's all about the seams.

 

[Peppie]

This is how I beefed up my seams

It may be over kill, but I sleep much better

 

[Krish]

Charly let me get you Derricks thread. He had some massive bowing and still uses the tank LOL! I'll search for it real quick for you.

 

[Krish]

Hmm...Can't seem to find his pictures. I know a lot of dealing with his bowing issues we dealt with in the chat room, but I will send him a pm and direct him to this thread and have him post up what he did and show you how much his tank was bowing. Mojo helped him a bit with figuring it all out. He did however start a poll on bowing you can find here. http://www.reeffrontiers.com/forums/f36/amount-bowing-your-acrylic-tank-59618/

In the meantime, I'll pm Derrick and direct him here.

 

[Herefishyfishy]

Smaller light weight acrylic tanks are built with the top and bottom supporting the sides in lieu of the thickness creating structure. If you removed the top bracing, would look like a balloon. The stretching causes crazing which is expected. Not a problem except for aesthetics. Larger acrylic tanks are 1/2" up to 2" thick. The really big ones like in zoo type settings can be a foot thick!

 

[Burke]

On my 125 gallon, I bought it used and was concerned about the seams. I reinforced them like peppie but less elegant. I used square stock. I have sand and the front corners don’t have seams, so it's not that noticeable and I can sleep at night.

 

[07FocusST]

Hey just a quick thought. I have a 10 year old 180 Gallon tank that has about 1" bow total on the front and back panels. For a 50 Gallon aquarium to have that much is kind of concerning as to the stability of the acrylic. My tank was made by TruVu and has a lifetime warrenty. It is also 3/8" acrylic with an extensive euro brace. I did end up taking it down to avoid potential disaster. If I were you I would empty the tank and consider another aquarium. As for me, I am going to turn the 72"x24"x24" tank into a shallow frag tank. Most likely 36"x24"x16" tank. Just need a table saw and router.

 

[akunochi]

Your truvu was fine. I had the same 180 built from 3/8" acrylic.

 

[Krish]

Hey just a quick thought. I have a 10 year old 180 Gallon tank that has about 1" bow total on the front and back panels. For a 50 Gallon aquarium to have that much is kind of concerning as to the stability of the acrylic. My tank was made by TruVu and has a lifetime warrenty. It is also 3/8" acrylic with an extensive euro brace. I did end up taking it down to avoid potential disaster. If I were you I would empty the tank and consider another aquarium. As for me, I am going to turn the 72"x24"x24" tank into a shallow frag tank. Most likely 36"x24"x16" tank. Just need a table saw and router.

Thanks for chiming in Derrick!

 

[charlypooh]

hmmm...lots of food for thought! thank you everyone!

 

[07FocusST]

Your truvu was fine. I had the same 180 built from 3/8" acrylic.

I agree but i have 2x 14 month babies with their high chairs sitting in front of the tank. Wife was concerned about the creeking the tank made everytime i made a water change. I still have both stands available to donate to the PSAS. If you want them then please get them soon otherwise I will have to destroy them and send it to the dump because I am moving out in a couple months.