We remodeled our boler, and put two seven gallon tanks in the lower cabinets of the kitchen. One gray water, one fresh. Hand pump leading from the fresh tank to the faucet. Easy to take out to clean. We have a fresh water fill from the outside, and can also fill by removing the tank. The sink drain runs to the gray tank. When we return home we dump it on our plants. We use bio soap only.
I did not want the icky water tank I could not easily clean out. We removed it and took it to the dump.
Omg, the mold that came out of the fixed tank was disgusting. I think leaks
From the water tank to the sink faucet was the source for much of the mildew behind the sink cabinet and under the bench in the rear where the line ran from the tank to the faucet. Soggy carpet and lots of smell. The really gross part? The previous owners had been using it when they camped right before selling it to us.
If installing and using a fresh water tank you MUST be super aggressive with maintenance.