Black rim on top of tank. How important is it?

[Milad]

Ive read some mixed feelings on how important the top black rim is on a tank.

I'm about to buy a 180g and it has a crack in the middle of the top black rim so its kinda freaking me out.

Should i be replacing it? who sells it?

Sorry guys if this has already been answered but I didnt find a good thread on it.

[Delphinus]

Generally speaking it is purely cosmetic and offers no structural support.

However that's only if it's the rim that goes along the outside. Some tanks have a cross brace that is part of this trim. In which case, the trim is doing a job of keeping the front glass from bowing out under load. But this can be replaced with a glass brace or better yet, "Eurobracing" (just reinforcing the outside rim again, but using glass, so there's no centre brace at all to work around).

[Milad]

so what the heck holds the tank from bowing and going boom?

This tank didnt have any bracing up top that i could tell. Should i look into eurobracing it?

[mr.wilson]

You need to establish the thickness of the glass first. If it's 3/8" or 1/2" glass, it should have a cross brace at the centre. If it's 5/8" glass, a eurobrace is a plus, but by no means necessary.

As Delphinus mentioned the black plastic cross brace is structural and not just to support a light or glass top.

[Delphinus]

The glass can withstand some amount of flex, how much it will see and how much it can withstand will depend on factors like thickness of glass used and height of the aquarium and so on. Bracing will reduce the flex. The black plastic trim however will have way more flex to it than the glass itself. Unless the black plastic itself has a cross brace, it's not doing anything other than maybe preventing someone from getting cut on an unpolished glass edge. If it does have that cross brace though then it is a different matter.

[banditpowdercoat]

The thickness of the glass is what makes it not go Boom. Plastic trim usually has no holding power. Even if it has a center plastic brace, chances are, It's not holding the glass from bowing. From tanks I have seen

[schroeder]

I have a much smaller tank (40 Breeder) and did not want the black rim, so I removed it. I did not like the look of the skinny glass edge on the top either, so I added 2" wide euro-bracing. LOVE the look of the euro-bracing! I was very carefull to mask either side of my silicone bead so that I have a consistent thin bead. Looks way better than the black trim and I don't have to worry about glass flex.

No photos sorry. The files got deleted accidentally.

[burrows14]

I was thinking about doing this to my 40 gal breeder Im using as a sump. Would it be less likely to have a problem with a tank that has 4 baffles in it?