Alright, I have a 125 gallon 72 1/2 x 18 1/2 x 23 1/2. I'm going to make my own background. I have all of the supplies, but have a couple questions. I'm hoping some of you that have made them already could help? Before I design it, I was wondering if I put a top shelf that sticks out far enough to put pillars for top dwellers, would that effect my flow? Using Fluval FX6 and a Fluval CP4 for flow. I was thinking of one on each end and one in the middle as far as the top shelves go and then some mid and lower in various places. The next thing is airbrushing. If I put a coat of quickcrete/drylock on after I have it designed, would my regular airbrush paints stand up to it when I go to put another coat of the drylock over it? Anyone ever tried that? I thought it would be easier for me to airbrush it. I also thought about making a ship or a cool broken sunken bridge if I could use the airbrush. Rust and green colors, maybe some barnacles? How is the drylock on small detail pieces? I know, just try it on a sample piece...just didn't want to waste my time if someone has already tried it.