acrylic tank question

[PTPuffers]

Hello, I just picked up a used Sea Clear Acrylic tank. 48"long, 20" high, and 13" deep. I set it on the porch and filled it with water to make sure there are no leaks, and I noticed it seemed to be bulging out a little bit in the front and back. I have never had an acrylic tank and do not know if this is normal or not. Does anyone know if this is normal? TIA

Gary

 

[mattseattle]

i've only owned one acrylic tank and it does exactly what you described. i don't know if it's normal or not but all i can say is that my 55 gallon does the same.

 

[Katchupoy]

I had 50g one too... and it does the same... so just to let you know...

 

[cookiemn]

Gary,
that normal with an acrylic tank. When I had a 65 tall AGA I noticed that the glass seemed to bow out as well. Or was that my imagination?

Erwin

 

[NeilsReef]

Hello PTPuffers, Your 55 gallon acrylic is probably made out of 1/4 inch acrylic (standard). I have purchased this tank new and seen numerous used ones. The new one from TruVu bowed very little, and after 2 years still bows very little. The used ones bowed quite a bit, many of the used ones had seen 7 plus years of service at my local LFS. They never leaked or busted apart even with all the bowing. Oftentimes I was only able to see the bowing while examining the tank from the side?
The tanks seemed to bow more depending on the temperature. For instance at a LFS during there major cleaning of the tanks they stirred up the substrate with a power head. They then proceeded to do a monster water change, and since there weren't any fish in the tank they didn't concern themselves with the temperature, which was fairly cold (the water came from an outside storage tank in the Pacific North West). I witnessed the tanks bowing even more, than they were prior to the water change. It could of just been my eyes, so please take this with a grain of salt.
Thanks for the question, and I hope this helps?

Neil

 

[big t]

I also have the same seaclear 55, fyi it is made from 1/4" material all around and does 'potbelly' quite a bit. I just got a new to me 90 tank that is 24 tall, and it is made from 3/8" and also potbellies out quite a bit. This is pretty normal for acrylic tanks. If you get a tank made from 1/2" or thicker they generally don't bow out nearly as much, but are much more expensive.

 

[Thefishcouple]

Here you go guys; that is normal for that tank. Almost all prodution acrylic tanks will bow, manufacturers like Sea Clear will use the thinnest possible sheet to keep cost down. I would assume that tank was built from 1/4 thick material that is the standard for 20" tall tanks, it should be fine.
John

 

[zeltar]

John, what thickness do you use for your tanks? Say a 4'x'2'x2'?

 

[Thefishcouple]

For the most part it is the height of the tank that determines the thickness needed. A 60 x 24 x 30" tall tank built from 1/2 will bow as much as the 55 built from 1/4 or the 120 built from 3/8. All are safe and should pose no long term problems. However if you prefer not to have any deflection then you should build up to the next thickness.
Zeltar the standard 48 x 24 x 24 is built from 3/8 material with a 1/2 top.

 

[PTPuffers]

Thanks you guys for all the responses. I will be able to sleep a little better now. Thanks again.

Gary

 

[Dr. Rick]

I have seen many of this area's "local guy's" tanks in use, and they all bow pretty good. This poses no threat as long as the joints are tight. So inspect your seams when you take delivery. To compete on price, manufactures will use the thinnest wall they can get away with. As the case with most tanks around here. As a whole, we need to spec. our own wall thickness, but this will negatively effect the wallet. My bad boy is 120"x 48"x 36" tall, and is built with 1.5" thick panels. Sounds beefy, and it is! If you have any doubt as to what thickness you will want, or think you will want, then PM me and I can get you in touch with someone who knows his stuff! My tank, at 80-81F., 1.025, and right about 890 gal., doesn't bow at ALL. Just ask the few of you that have seen it. Bottom line, if you want a masterpiece, and don't want it to bow, or leak, then be willing to pay the piper, and have someone who knows what there doing build your tank. The Rick

 

[cookiemn]

Lets not start this again. It would be nice if you gave some decent advice without ripping anyone rick. One thread I started about acrylc tanks was taken of line because it got heated with your comments and blatant advertising of "someone who knows his stuff". It would be nice for a change if you just post your comments and not try to advertise for anyone while trash talking one of our sponsors. Who BTW makes excellent tanks. If he didn't he would have gone out of business a while ago instead of being backed up with job orders. I will admit that I am currently waiting for John to finish my tank. I did my research on who to build my tank and John was the best option. One thing that I took into consideration was that some of the PSAS staff members had their tanks built by IAP. Mojo's tank was built by IAP and is displayed on IAP's web page. I believe that Nikki also had her tank built by IAP. This fact alone made up my mind for me. If these VERY experienced reefers had tanks built by IAP that's good enough for me since they know a whole lot more than me and you combined. Not to mention they have a lot more to lose if they thought their tanks were not built right. If you look at iapjohn's reply he doesn't advertise his tanks on this thread he is just trying to help the guy.

The Erwin

 

[Elmo18]

This is normal. My 75 gallon acrylic also bows a bit, and can be seen if you look at it from the side.

Wait, Nikki? Who is NIkki? wat? o hahahaha

j/k Nikki, just felt like I needed to joke a bit.

- Elmo

 

[Thefishcouple]

Rick
I think you are confused over what is standard off the shelf aquarium and what is a custom aquarium. Companys like Sea Clear and Tenecor and Clearity and so on build for the masses. That is the market we targeted when we started and we still produce those today and will continue. If you want to compete in that market then you must build a simalar product it dosn't make it a bad product just less expensive. Most aquariums are built for things other than reef tanks. Someone that is setting up a 55 gallon tank for the first time could not care less about thickness of acrylic or will it bow slightly. How much is it, does it fit my budget, will it work for me now? Those are the concerns of most people. These products are not inferior they all work well and last a very long time. Toyota also builds Lexus and by doing so it dosn't make the Camry and crappie car. We always build what the customer wants. If he wants a 55 gallon tank built from 1/2 acrylic than great. If you wanted your 10 x 48 x 36 built out of 2" than thats what you would get and it won't leak either. So when you reefers are ready for that bad boy 1.2 gallon masterpiece nano tank built from 3/4 Polycast acylic PM me I know someone that can do that. Your wallet won't feel nearly as deflated either gauranteed. And once more for those thousands and thousands of standard off the shelf acrylic tanks out there BOWING IS OK. After all that was the question wasn't it ?

 

[cookiemn]

Well put John. I upgraded my 90 from 3/8 inch to 1/2 inch because I didn't want it tp bow.

PTPuffers, you will soon notice that only you will notice the bowing at first. Everyone else who looks at it will never notice it because they will be more interested at looking at your livestock. As John said, if you want a tank that will never bow you need to increase the thickness of your acrylic. I estimate that when I upgraded and got a custom tank I paid nearly 3X the amount that I paid for my Sea Clear tank. But, I got a coast to coast overflow and specified the thickness of the tank. I had a 60 gallon Sea Clear that I just sold (48x15x18) to Colleen recently. Sea Clear makes a decent tank, but if you really get hooked you may want a bigger tank. I think that's everyone's story here.

 

[wooddood]

if those tanks had euro bracing around the top they would'nt bow would they?

 

[Thefishcouple]

Wooddood
They are referring to the front and back panels of the tanks. Typically acrylic because it is flexable when under presure will form a shape not unlike that of your T V screen. Even very thick panels on large aquariums 3000 plus gallons when veiwed from the end along the panel will show some deflection. It is actually one of the tendencies that makes acrylic superior to glass. Glass will also flex or bow but cannot flex as much as acrylic before falure. .
John

 

[cookiemn]

Do rounded corners on acrylic tanks a concern versus just gluing them at 90 degree angles like the glass tanks?

 

[big t]

Cookie your question makes absolutely no sense, please restate it!

 

[fishermann]

cookieman rounded corners is 2 less glued joints you have to worry about if that is what your'e asking and i think they look better.