Drawing down dual water tanks

[valhalla360]

We used to have 2 tanks and it would depend:
- Ours were level so one tank draining to the other wasn't an issue.
- At dock, we would open both so that the tanks were regularly turned over with fresh water.
- At anchor/under way, we would work off of one tank at a time, so if there was a leak or other issue, it wouldn't drain off all our water.

[waterman46]

Originally Posted by bobgarrett

If you draw from both then whichever empties first may then result in your pump just sucking air so that even though you still have water it will not be available.

Yes, and you must have a separate valve for each tank. You want to open only one tank at a time. When first tank is empty, You will suck air which tells you half your water is gone. Then close valve to first tank and open valve to second tank. Fresh water pumps are self priming, so after a few seconds running on the second tank, it will prime.

[robert sailor]

Originally Posted by Scrimshaw4

If the settee tank doesn't cause a notable list then I would draw down from the bow first to take the weight out of the bow. JMHO

[djousset]

Thanks all, very helpful!

[Moontide]

I have two tanks and draw on one at a time, rotating the draw. Half out of tank 1 then half out of 2. If you empty one tank and then a hose breaks or someone leaves a faucet on you can drain the 2nd tank and end up with zero.