HD and Ace carry rigid tubing, ask for refrigeration drain lines.
I have about 40 3ml pipettes...if you (or for that matter anyone) would like some, let me know. I get them free from work and use them for dosing, feeding, and testing...I always keep a few in rotation to cut back on contamination, especially with food. The tapered ends fit right inside the tubing.
I usually use a syringe for feeding meaty foods since its easier to push thru than using a pipette...but they should still be useful for your purpose. lmk...I'll bring a bunch to reefstock in case.