I'd get a tug the same size and cut it down to 1 - 2" tall and fill with crushed ice and sit the DWC tug on it. That would work and tugs that size are cheap so you could have two. Easier to replace a thin tug full of ice than to remove and fill and replace. that takes time. It'll work if you have the headroom.
WJ
I just remembered that I was going to pick up a couple of these tugs anyway and use them to raise the plant closer to the lights because I could not figure out anything else to use that was not a fire hazard in there.