I bought some of the watering nipples an Tees on Amazon as Clay mentioned and installed my rabbit watering system last year. I wish I had done it years ago. I used 5 gallon bucket on a stand. When it is warm enough to use the automatic watering system, it saves me so much time. I love it. I use bowls in the winter because bottles freeze up too fast and the automatic system nipples would too. I am in Ohio. We ran out of tubing so we bought some more at a local hardware store. I hadn't seen the watering system at Rural King or I probably would have bought it there.
I bought the bucket connectors
https://www.amazon.com/Bucket-connectors-Rabbit-Nipples-Gravity/dp/B08716S9R1?pd_rd_w=VbD59&content-id=amzn1.sym.724fac2e-0491-4f7a-a10d-2221f9a8bc9a&pf_rd_p=724fac2e-0491-4f7a-a10d-2221f9a8bc9a&pf_rd_r=G47SZVZM6YM2QAXQ7FMT&pd_rd_wg=6twV7&pd_rd_r=639a6eb9-556a-49e8-81b0-9e2d3d205d51&pd_rd_i=B08716S9R1&psc=1&ref_=pd_bap_d_grid_rp_0_29_i
and I bought the nipples and tees.
https://www.amazon.com/Junniu-Automatic-Drinker-Drinking-Watering/dp/B09DKPRC89?pd_rd_w=VbD59&content-id=amzn1.sym.724fac2e-0491-4f7a-a10d-2221f9a8bc9a&pf_rd_p=724fac2e-0491-4f7a-a10d-2221f9a8bc9a&pf_rd_r=G47SZVZM6YM2QAXQ7FMT&pd_rd_wg=6twV7&pd_rd_r=639a6eb9-556a-49e8-81b0-9e2d3d205d51&pd_rd_i=B09DKPRC89&psc=1&ref_=pd_bap_d_grid_rp_0_50_t
I had plenty to run the system to 10 cages with some left over. I have had one or two nipples not work right and replaced them and still have some left over.
I live in North Central Ohio. This watering system gives me great piece of mind in the hot summer months so I don't have to fill water bottles multiple times a day. Works great April through about November. I use bowls in the winter because even if the water freezes, the rabbits will still lick ice and get moisture that way. If I use bowls in the summer they tip them over and don't have water. They will also go through several bottles of water a day when it is hot. I raise Champagne d' Argents and I keep them on the north side of the house so they only get sun in the morning.
You can make the system automatic by adding a float valve to your 5 gallon bucket or reservoir with a hose attached the float valve. I haven't done that yet because I have to be able to move the hose so I can mow the yard.
I kinda wish I had used black tubing to limit algae growth but I went with clear tubing. At least I can see if there is crap building up in the tubing. When I see stuff building up in the tubing I pull the tubing off a tee and let it run the crud out.
I did make a few mistakes at first, having the tubing too close to the rabbit wire......yep the rabbits chewed it and of course the water all drained out, but after a couple of those mishaps, I got things right and all is going good this spring so far.
Again, I wish I had done this years ago!
goodluck!
Bonnie