that being said.. here in the great flood plans of California I’m required have my grey water tanks 50% bigger then my fresh water tank. and since my grey water is @ 40 gallons. I’m planning on buying @ 25 gallon fresh water tank. and I will also need a pump. so I’m looking for any recommendations or links would be great. i cant afford the top of the line equipment but would like something decent and dependable. thanks in advance.

50% Larger? That seems way high. In my area it is more like 15% larger for grey.

For a pump go 12V Flowjet. Excellent pressure. Simple and cheap to fix if ever a problem.