water tanks

Pick up in Salt Lake City. I'd prefer to sell the solar set up as a single system. Intial post had 2 AGM batteries included, but just tested and they wont hold a charge.. Thanks, Kent Solar System $200 100 Watt Panel (Grape) with 10 foot 12AWG duplex cable and SAE fitting Morningstar SunSaver...

I'm not sure how to think about grey and black water tanks for my box truck conversion. Does anyone know any good sites for how to install them? I haven't chosen my toilet yet... if it's a composting toilet then I may not need a black water tank at all, which is preferable.