So I want to do a small retaining wall in corner of my 20 gallon to raise up my ADFs feeding dish for easier reach and as well as I think it will look cool. I was scrounging around trying to find an idea of how I can make one. I found some scraps of vinyl skirting that would work perfectly. Sturdy yet cutable with sharp scissors. I plan on scrubbing it then boiling the pieces to be safe. However WILL it be safe in my aquarium? I can't find anything anywhere to tell me, just on vinyl tubing. I was thinking about maybe using silicon and sand or pebbles to cover it, but its white with a wood grain texture so it might look nice the way it is. Anyone have thoughts to th safety or anyone tried anything like this? Please advise me asap as i am anxious to start this or continue looking for something else to use.