Bev, as Steve said, it's more an overheating issue than an electrical issue with heaters.
And ironically, the only tank I ever had drain was the one tank I've owned without a sump. The external filter got a loose connection, and drained 90g of SW into my carpet.

what does unsuported bottom mean? i can see the plastic surround on the bottom, isnt that the support? my 90 is euro braced around the top but i don't have any cross pieces in the bottom.. what am i missing?

Some people think that you should have a full platform under your tank. Personally I don't, I think support around the edges is fine. That's how my tank is and all the water has stayed in so far. :razz:

Geez, I remember that :cry: It was during a summer heatwave, too, wasn't it? Makes me want to check the temp of my tanks daily :eek:

I think it was the way that tank was supported for sure, look at the pictures it just doesn't make sense the way it was done. IMO it should have been supported under the entire surface of the tank.

I would not let that thread sway you to have a sump or to drill or not drill.

Dave

so if there was a full sheet of plywood under the tank then that would be considered supported as aposed to a metal framed stand that only supports the edges?

If you're going to put a sheet of Ply under your tank go the extra step (and it's cheap) and put a sheet of foam insulation down between the tank and the ply. The foam will support the tanks actual glass bottom and if the ply warps or does anything else funny the foam will absorb it.
The heater issue is why some people like to use two smaller heaters rather than one that's rated for the tank, IE rather than a 250 use two 150s. Most heaters are recommended on the idea that you need to raise the tank temperature by (I think) 5-10 degrees, so they recommend 5 watts/gallon. This means a 5 watt heater that's rated for a 10 gallon tank shouldn't work on a 27 gallon tank but as long as the air is room temp and the tank isn't a discus tank, the 50 will work nicely. I used a 250 on my 150 gallon and it was great. I've got a 10 gallon tank I'm using as an incubator in another room and a 25 watt heater is holding the water in there at 95+ degrees.

Doug

And some times worse can Happen I have had a heater exploded before and release a brown cloud of death through the water!!

I have not yet read about this! Could you explain :biggrin:

Those are my thoughts as well. Regardless of how the connections are configured, the bottom pane supports the vertical load and the sides hold the water laterally. I can't see how a foam insert below the bottom pane would not be a benefit. What is supposedly happening with the forces in the opposite scenario?

But yeah, just about the worst place to drill the bottom pane, right in the middle...