View Full Version : Silly Question about 40B

Girly Gears
01/25/2011, 02:27 PM
Does a 40 breeder need foam under it? I'm not sure if I should cut it to fit inside the plastic trim, or make it come out past that. Also is it better to put the foam directly under the tank or put foam under some plywood and have the tank on top of that? Post pics please... I'm a visual learner for sure lol...:thumbsup:

01/25/2011, 02:31 PM
A typical glass 40b has a rim around the bottom (the bottom pane is "between" the sides, instead of the sides being "on" the bottom). It needs no foam. In fact, using foam on a rimmed tank can cause damage (if the foam contacts the bottom pane of glass, it can crack it).

What you need is a level, planar surface to support the four corners with no gaps.

Girly Gears
01/25/2011, 03:51 PM
Sweet, just wondering cause I saw a 40 rimless with foam and got to wondering if it was necessary. Just compiling my build shopping list and making sure I wasn't going to have to tear down a tank due to a crack...

01/25/2011, 03:53 PM
All my rimmed tanks, including my 40B tanks, sit on foam. Always have, never had an issue.


01/25/2011, 03:54 PM
Yeah no foam on tanks with a rim.
Rimless or acrylic put foam under it.

Girly Gears
01/25/2011, 04:26 PM
Hmm...I was thinking if I put the plywood on top of the foam it would be ok, I just want it for padding. I have two tiny hooligans running loose in my house and I have wood floors. Was hoping it would cut down on vibrations and noise for my fishes.

01/25/2011, 06:55 PM
I have foam under mine. My stand's top isn't perfectly level, so I put the foam down, put the tank on it, filled it, let it settle and then ran a razor around the edge. I just cut a trim piece to fit around the foam so it's not visible.

Gold Stripe
01/25/2011, 08:57 PM
Rimed tanks are specifically designed so that the rim (Particularly the 4 corners) supports the weight of the tank. By putting foam under the tank you allow the bottom glass to bear some of the weight and risk creating a "hot spot" that may cause a crack. Because only part of the tank's weight is on the foam, the weight may be distributed unevenly. This is rare but it can happen.

Rimless tanks are specifically designed so that the bottom pane of glass supports the tank. You put foam under them so that there are no "hot spots" that might cause a crack. Because all of the weight of the tank is on the foam, it assists in evening out the pressure to the whole pane of glass.