It's pretty easy you need
5 gallons bucket can be bought at any walmart, home depot etc for about $5
Tank connector
Valves (one per tubs or cage)
Some T fitting (same amount as your valves minus 1) and one L fitting
Mounting clips (as many as the number of valves)
Clamp loops (about 5 to 10)
and tubing
Total for a 6 tub rat rack for example will run you just under $50 with some extra tubing and it is worth every penny.