Demountable camper group

Hi all,
The questions are popping into my head regularly now that collection date is coming into view
Having only having owned an old motor home which had holding tanks onboard for fresh and grey water + cassette toilet,I'm now wondering what the set-up is for the water from sink and shower.....is there onboard storage or is it a reservoir like I see caravan guys using?
Recommendations for suitable products gratefully received.
Our unit is a Northstar 750DL
Thanks all

Not sure if the newer models are different but my 750DL doesn't have a grey water tank, just drain holes underneath, one from the kitchen sink and one from the wetroom.

Previous owners used a couple of runs of hose and one of these.

Thanks Rob,our camper is approx 10 years old so won’t have an internal grey water tank.
I'll pick up a reservoir locally if possible.....I’m sure the wife has an Amazon account although I'm not a fan myself.

The problem is gravity, isn't it. In a motor home, there is space under the sink or shower, low in the chassis.

I've often wondered about stowing water tanks under the bed the way some people load LPG.

I'm sure it could be done.

The Suntrekker is a very small camper so we do not have available storage space onboard for waste tanks, so we have a compact solution.
I did not install the system the original owner did. Our sink unit waste is piped to the rear of the unit on the external rear corner is a down pipe at the bottom is a T piece linking to the shower drain and short open pipe. We then hang a folding bucket below using an S hook onto one of the unused tailgate fittings.

Jon