I had the same issue with the nipple system, I liked the idea so I tried the cups. Filled the cups up once with my finger and let them figure it out in which they did rather quickly. I won't ever use the nipples again, glad I monitored them for a day because some had severe signs of over heating with nipples. No such issues with the cup. Side note, can the nipples be removed from that model??Well I could not get my chickens, to drink at all from the horizontal nibble heated water bucket at all. I showed them many times during the day, but they just didn't get it, so I put a bowl of water in the run and they would drink like they just crossed the Mojave Dessert....
So I took the heated water buckets back and got heated dog bowls, my chickens are very happy now
After watching the movie Moana, I was a bit upset about how the chicken was portrayed....but now I'm wondering if they were right on the mark, since my chickies could not even figure out the horizontal nipple water system...