First, find the leak. If you have a puddle it shouldn't be that hard to find the source. If it's a small wet spot then you'll have to look harder. The most likely spots are connections: Inputs and outputs and don't forget splices in those lines. Any of these is a more likely source of a leak than a crack in the tank itself. Also look behind any structure that blocks your view of these. I found a leaky fitting on my potable water tank that was behind a sheet metal panel held in place by a couple of screws. The rust on the screws tipped me off that there was water behind that panel and sure enough that's where the leak was. Investigate.
Also, make sure that it's fresh water you're seeing. Just because the water appears near the potable water tank doesn't mean that there aren't other potential sources in the area or that the liquid isn't traveling from its source along an interior wall or frame member. Investigate.
Lyman & Deb; Chip & Charlie (Portugueses Water Dogs); Portland, Oregon
2004 Itasca Horizon 40AD
2015 Jeep Wrangler JK