I measured the glass bottom of the 125 with a 6-foot straightedge and a feeler gauge and it is very flat.
If I set this tank the way it is it will only touchdown on the four corners of the thick plastic trim. I haven't put any water in it yet but I doubt that it's going to flatten out in any meaningful way.
I have two 55 gallon tanks setup like this and they only rest on the four corners. Another fish keeper with a 125 advised me that this was okay. So far no problems but it hasn't been very long. A few months for the oldest. I hesitate to set the 125 this way.
In fact what I want to do is flip the tank over, and sand off about one millimeter of plastic in the corners. I suspect it's ~2mm thick where it touches down. It feels much much thicker than the styrene trim on my other tanks and I do not believe it is ABS, but instead PVC plastic.
Because the tank sit's so close to the wall I am having a difficult time measuring the gap in the back but I can tell that it exists by sliding a paper through from the front.
This will make it too difficult to sand the trim into perfect contact with the wood in a most critical spot.
So I am going back to my original plan which is to set the trim in rigid bedding compound.
I think that this camber was built into the tank on purpose, and it has everything to do with the cheap commercial stands that they sell to go with it.
It looks as if this is a positive method of preventing the tank from rocking in the center.
The warranty instructions from Visio says that the tank must have full and continuous support around the rim.
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