Top brace cracks

Terrence Henderson · Oct 29, 2018

I have a 90 gallon system (48"x18"x24"). The aquarium is filled with water. I got this tank for free from a friend and it had cracks on the top when I picked it up. He had no problem with it. It is filled with water, sand, and live rock. The tank has 3/4" thick glass. Should I be concerned about this top brace? I so what can I do to repair it?

Synodontis · Oct 29, 2018

Looks like a plastic brace to me?
If so I would expect the brace has no real strength to it, just used as a surround to cover the top glass edges.
If it is plastic, if you have the brand of the tank you might be able to source a replacement.
If it's a glass brace, I would replace the tank

Retro Reefer · Oct 29, 2018

Probably won’t be an issue from what I’m seeing in pictures, you may have been able to do some kind of repair before refilling tank but that would be difficult now.. I would check to see if there is any “bowing” of front glass with a straight edge and keep a close eye on it.

puffy127 · Oct 29, 2018

I had a cracked brace on my 125g. I ended up replacing the top frame. If you know the manufacturer of the tank, you might be able to buy a replacement from them. If not, you can buy one here: http://www.aquariumframeswholesale.com/

I followed these directions for removing the existing frame:

It's a lot of work to replace the top frame, but well worth it for the peace of mind.

Pntbll687 · Oct 29, 2018

It is plastic, but molded into the frame. You dont "have to" replace it, but the tank was designed with it for a reason. Just because you can remove a frame or brace from a tank and be ok doesn't mean its a good idea.

The major drawback to these are that to replace it, the whole frame needs to be replaced.

flooddc · Oct 29, 2018

Definitely need to be replaced. Since the tank is a framed tank, a center brace is there for a reason. It's prevent bowing that would stretch the seams and thus the integrity of the tank.
Some people has removed the frame to make into rimless and claimed no issue, but why risk it when you have $$ invested into it. Not to mention damage to your home should it sprung the seams and it will sooner or later.

Pntbll687 · Oct 29, 2018

It's also better to replace it now, while you're just setting up and getting started. It could last years the way it is, but no one wants to break down an established reef to replace a brace..... and then BOOM a seam busts due to the added stress from not having a center brace

Terrence Henderson · Oct 29, 2018

Pntbll687 said:
It is plastic, but molded into the frame. You dont "have to" replace it, but the tank was designed with it for a reason. Just because you can remove a frame or brace from a tank and be ok doesn't mean its a good idea.

The major drawback to these are that to replace it, the whole frame needs to be replaced.

I kind of figured with the thickness of the glass and no bowing in the front this tank would be fine. Just needed some guidance because this tank was free and my friend had no problems with it.

Erica-Renee · Oct 29, 2018

Those Cracks that are not close to a Corner or near the brace is not really a issue as long as its tightly held by the silicon. The stress cracks by the Cross brace on the other hand is something you SHOULD Watch.. I Think getting new Trim for a 90 is not difficult , If it were me i would replace it n0w instead of being frantic if the brace cracks get worse..

Good Luck

Terrence Henderson · Oct 29, 2018

Can I use some plastic welding epoxy?

Erica-Renee · Oct 29, 2018

Terrence Henderson said:
Can I use some plastic welding epoxy?

If you can find some for that blend of plastics . But if the brace is cracked in many places my thinking is its been exposed to to much uv and is Compromised... This is why i think euro-bracing is a better fit for Reef TANKS

Terrence Henderson · Oct 29, 2018

Erica-Renee said:
If you can find some for that blend of plastics . But if the brace is cracked in many places my thinking is its been exposed to to much uv and is Compromised... This is why i think euro-bracing is a better fit for Reef TANKS

Would it be better to get a 3/4" sheet of glass and silicon it under the center brace?

Erica-Renee · Oct 29, 2018

Terrence Henderson said:
Would it be better to get a 3/4" sheet of glass and silicon it under the center brace?

NO!!

You would have to Put a glass rim all the way around the interior of the tank then silicone the brace to that and the tank. Otherwise you will not have enough glass to glass contact to hold the pressure ..

Terrence Henderson · Oct 29, 2018

I may just take the safe way out and order a new top brace. Will draining 1/2 the water work when replacing the brace with water in it.

Pntbll687 · Oct 29, 2018

You can swap it out for a glass brace if you want. Just get a piece of glass cut to the same size as the brace (maybe a bit wider) and silicone it in place, using the plastic brace as a guide. Wait 24 hrs, then use a

Terrence Henderson said:
I may just take the safe way out and order a new top brace. Will draining 1/2 the water work when replacing the brace with water in it.

I would drain it down to 1/4 if you are going to leave water in it. You want to get the water as low as possible. The safest way would be to totally drain the tank.

don_chuwish · Oct 29, 2018

Terrence Henderson said:
I have a 90 gallon system (48"x18"x24"). ... The tank has 3/4" thick glass.

I assume you meant 3/8" thick glass?
And yes, the brace is structural. No it's not fixable in place. If you COULD get a top frame replacement from somewhere then you could do that, but I know Aqueon stopped providing them due to counterfeit tank issues.
From experience, I'd suggest a new 90G tank.

Terrence Henderson · Oct 29, 2018

don_chuwish said:
I assume you meant 3/8" thick glass?
And yes, the brace is structural. No it's not fixable in place. If you COULD get a top frame replacement from somewhere then you could do that, but I know Aqueon stopped providing them due to counterfeit tank issues.
From experience, I'd suggest a new 90G tank.

It is 3/4" (.75") thick glass. I was surprised about the thickness. I'm trying my best not to purchase a new tank. This tank is good quality, reef ready, and got it for free. I will just purchase a new trim from http://www.aquariumframeswholesale.com/

Captain Quint · Oct 29, 2018

Is it a portion intact that extends? You could easily do what I did on my 125g I sold to a friend. Still holding strong at 8 years after acrylic bracing.