Each main tank is going to have two lines and the hopper will have three. I use 3/16 brass with the next size up in 1/4'' lengths to make a retaining nipple on the ends so the tubing cannot slide off. Each main tank will be set up as normal with a clunk and a vent that reaches the top of the tank to allow full capacity of the tank to be used. The hopper will have a center pickup or filter clunk that goes to the pump, a fill line and a feed line from the mains, these two lines should be short in the tank so that you again get full capacity. going from the hopper back this is the way it should work. the feed line of the hopper will go to the clunk of one main tank and the vent of that tank will go to the clunk of the second main tank and its vent will go overboard. I left a small amount of brass hanging out to hook up an overflow tank. I used tygon tubing and safety wired all connections just to be sure they stay put. Hope this helps. Here is a few pics of the stingray tanks that should clear everything up for you.

Chris