Hardwood floor and fish tank

[lochaber]

Originally Posted by Diana

I like the initial "Oh yea!" of the basin (2 x 4 and plywood). It would indeed catch a lot of water, and you could probably arrange a drain to get the water outside safely.

However, it does not breath under the plywood, so if water ever got under there it would stay. It would mold, deform the wood, ruin the finish...

I prefer the ideas above for making as little floor coverage as possible, and moveable (sliders) at that. ]
I see the OP point, too. I also have 125 gallon tank, 20 gallon sump on newly finished 60 year old real oak hardwood floor. Also a 72 gallon bowfront with a 20 gallon sump over the same floor.
Both of the stands are DIY, and have feet the full length of the tanks.
I glued felt under the stands. I was of 2 minds while I was doing it.
a) Will hold moisture, wick it in, but it would also evaporate right back out.
b) Felt against the hardwood would protect it from getting scarred.
Point a) was a wash (pun intended!) Felt might help the water get in, but would just as easily let it back out. Point b) became the deciding factor.

Yeah, I'm mostly hoping to just prevent water from getting underneath there to begin with (not the best of plans, but...) Once I get it set up, I may see about putting some sort of removable caulk, or even weather stripping around the edges to prevent the occasional spill splash (more likely from me carrying something then the tank itself). from creeping under.

I made some adjustable feet with sliders from my stand out of t-nuts, elevator bolts, and some furniture sliders. I'm pretty happy with them right now, and they hold the stand something like ~1/4" off the floor, and hopefully will work better for leveling the tank then shims and such when I finally do set it up. The two on the right are finished, I had to sand down the edge of the bolt head a tiny bit to get a really nice fit with the sliders. The one on the left is pre-sanding (blue tape to protect the threads from the chuck).

[Diana]

The bolts and feet idea that you have will minimize the amount of water under those feet, and any water that does get under will evaporate quickly. But that is a lot of weight to put a large tank on just 4 or even 6 of those feet. I would be concerned about denting the floor.
However, if you are using these inside the plywood box, then dents are of no concern, as long as they dent evenly, or you check and adjust to keep the tank level should be no problem that way.

[PlantedRich]

It's a bit of a gamble, either way we go. I had thought of using a small bead of clear silicone but then it is not an idea that I have tried on a nice shiny new floor. a nice small fillet of silicone run all around the crack at the bottom might be the thing to keep water out. But then how well does it come off when you want to move? It may leave some trace of the line but is it enough to be a problem when we look at what is likely to happen under the stand anyway? Will the floor under the stand be the new color and the rest weather over time? This happens with carpeting and vinyl but I've not looked at new wood flooring.