Very nice. Sounds like I'll keep them in a separate container for 1wk (feeding them algae pellets or the like), then add them to the tank for 1wk to perform their cleaning. That's a plan.
Regarding the CO2 generator, I built one last year for the aldrovanda with a less risky setup. Simply take a 1-2L plastic soda bottle and add 3 cups white granulated sugar, 1 tsp yeast, 1 tsp baking soda, and fill the rest with distilled water up to the shoulder. Punch a hole thru the cap and run plastic aquarium air tubing through it so that it ends 3" above the waterline. Use caulking agent to make an airtight seal. Screw the top onto the bottle and wait 30min. Insert the other end of the tubing into the aquarium, and pure CO2 bubbles will come out. The apparatus will sustain itself for 30 days before a new solution has to be poured in.
My plants and I thank you all again again for the help.