Huzzah! A solution materializes.

after chats with various people, the idea emerges that, as the pump costs the most, that needs to be tackled, eg ONLY HAVE ONE.

use flow control through valves or something to limit what is being sucked up by the pump.

clamp design:

so... Pump ordered, and tube, now to dig through the parts box and see if i can knock something up (clamp-wise)