I use the water cups to water my girls thats hooked to a 5 Gallon bucket. the only thing I did different was to put a shut off valve at the end of the pipe so that I can drain off the water without unhookig everthing. every other day i drain the old water out and add fresh to the bucket. My bucket and pipe are both white and I haven't had any problems with alge doing it this way,and I just feel better about knowing their water is fresher.