Broken center braces

[DiscusnAfricans]

I've seen some posts recently where people talk about a broken center brace on their tank. Some people act as if you have to replace it right away, and if you don't, the tank will explode.

I bought a 5' 120g tank about 5 or 6 years ago, and it has been running the whole time. When I bought it, the center brace had been broken out because the person was using the tank to culture live rock.

I bought a new top frame for the tank, but never got around to replacing it. I have not had any problems with this tank, but am concerned about the possiblity of 120 gallons of water bursting through the seams.

How important are center braces? The tank does not seem to have extra thick glass, and has not shown any signs of bowing or other degradation.

Anyone have a negative experience with a tank missing a center brace that was originally built that way?

 

[Tony]

Still have your replacement frame at my house, Mikey.

Personally, I'd change it. I've seen glass on smaller tanks (55) with broken center braces do crazy things.

 

[gravel_digger]

personally i wouldnt take the chance. i dont think i could get my wife to forgive me on this one after she figured out the full story....

 

[Avatar]

Eye test

Sight down the length of the tank when it's full and see if you detect any bowing along the top edge which would indicate and translate to stress at the seams and on the panes. I did this on my 55 after last year's tremor when the brace snapped and was shocked at how much both the front and back of the tank were bowing - like around an inch+! Put a cabinet clamp on it until I could get a new frame.

Seems like mostly it will depend on the glass thickness and possibly the gauge/stiffness of the top molding. Conceivable that it's not a problem and that the center brace was there more to support glass tops rather than to supply critical structural integrity. You could also take something you know to be straight and place it against the top edge of the glass and see if it lays flat. That will give you a pretty precise measurement of the amount of flex along the length of the tank.

My 55 at issue has 1/4" thickness front and back (ends are thinner) and the plastic top molding is all for show without a center brace. It's also 21" high and the taller the tank the greater the pressure/stress. All tanks are definitely not created equal, but if yours is 20" tall and uses 1'4" plate, could be an issue - especially if the ground starts rocking.

Eye test - and let us know what you see.

 

[jonclark96]

I had the same experience as Samuel. I picked up a used 55 with a broken center brace. I test filled the tank to see if it was a leaker before setting it up in the house and the glass bowed an inch at the midspan of the 4' piece of glass. Way too much movement for me to be at ease, plus the hood didn't fit right.

I wouldn't risk it on a 120, even if you aren't seeing any bowing right now. Replacement of the frame is relatively simple.

 

[Pat Kelly]

I need to replace a couple of my 55's.
One of them has been split about 2 years now. I am pressing my luck. The other almost as long but the glass is up against a brace near the middle so that is holding some of the pressure.

They are both around 21 years old.

I better replace them before I come home and fine 100 peacocks dead on the floor. That would stink..... both ways. lol

 

[DiscusnAfricans]

I'll have to measure the glass to check the thickness. I'm sure the tank is 24-26" tall. I've had a canopy on the tank for the past 3 years or so, guessing this might serve as additional support, though I'm not sure how much.

Will try to get that frame from you ASAP Tony, sorry its too big to fit in my Corolla.

A lot of my hesitation was not having the time to replace the frame without the tank running. I'd have to at least remove the HOB filters, canister lines, and drain the tank part way to have a chance to replace while fish are still in it. Not enough tank space to transfer everyone temporarily, and not enough time during the moves.

Haven't noticed any bowing, but haven't really been looking for it either. Hard to imagine a narrow, thin strip of plastic provides that much support compared to the weight of the glass, but I'm not the structural engineer.

 

[Avatar]

The wide wide world of sports

Not support - tensile strength. You could snap that brace lengthways in an instant but you'd grow old before you were able to pull it apart.

I did my 55 with fish in it just as you describe, silicone and all. Framing on a 120 might be pretty stout - might be good to have a cutting wheel or some such on hand to sever the plastic at the corners or anywhere else where its stubborn. Good hunting.

And I'm still interested in whether you can see any bowing using the eye and/or straight-edge test.

 

[Pat Kelly]

I had to replace one of my 55's that had the brace broken yesterday.
I was doing a water change and as I was filling it I heard a pop and a 2 inch piece of the front plastic frame popped off. Center brace was already broken but it broke part of the front. You could see the glass had bowed even farther.
I put the water down a couple of inches and then went on a 2 hour search for another 55 (another story in itself)

Got her changed out before she cracked on me.
Like I mentioned before, tank was like 21 years old.

 

[jonclark96]

Glad you averted disaster, Pat. The way I figure it, if the manufacturer thinks the tank needs a center support, it probably does.

 

[Avatar]

Scary how much the glass can bow on a 55

I put the water down a couple of inches and then went on a 2 hour search for another 55 (another story in itself)

Should have called - I have an extra I was going to put on a 33 long (so I can put glass tops on it) but it doesn't really need it for integrity/support. They're less than $10 apiece online so it made sense to get three since shipping (around $10) is about the same either way.

Now that I think of it, seems I gave one of mine away to someone in similar straits for an assurance of future consideration and as such I demand to know if I ever received satisfaction. You, you unknown beneficiary of my boundless generosity, tell me, am I/was I ever satisfied?