For all those that have asked me about my plumbing system on my rat racks, and their construction, here is the best photo journal I can come up with for now. I am planning on building a page on my website soon for DIY Rack building of rat racks, rat cages, baby ball racks and adult ball racks. On to the picture show.
Front shot of the racks.

Side shot of the racks.

Plumbing on the bucket. I use a 1/2 inch male threaded connector to go into the hole drilled in the bucket. Next I put in a 1/2" Tee with a cap pointing up, with a hole drilled in it. I believe that the clear tubing I use as a sight glass is 1-1/4" tubing( it may be 1-1/2, I can't remember). From the tee, I install a 1/2" valve, to shut off the water in case, and then into a 1/2" threaded union. Sometimes the 1/2" union is hard to find, in which case I use a 3/4" union with step downs installed back to 1/2". All of this allows me to disconnect the bucket even it is full to do repairs to sipper valves without constant water.

Second shot of ther bucket plumbing.

The seal that I use inside of the bucket to keep it from leaking. I get these rubber seals from ACE hardware. Essentially it is a big rubber washer. The PVC piece shown in the bucket is a female threaded union threaded onto the male union coming from outside. Just remember when screwing on the female union to put teflon tape on the male connector, or the friction will get to high before the connector is all the way tight.

The plumbing on the top of the rack that connects to the bucket.

The plumbing for each level.

The plumbing going to the sipper valve. Those are the threaded sipper valves. I drill a hole in 1/2 inch PVC cap and wrap the valve threads with teflon tape and thread them into the hole in the cap.