Hydroponics is a great hobby - after you understand the principles, you start designing systems with available materials. It is like inventing the wheel over and over and over...

I thought about using a razor knife, but thought it was going to leave jagged edges, that may rip or tear with weight and heat. I came up with the compass cutter from a tool I purchases to draw 11 foot radius circles for a church window I made. The tool is designed to hold a center point pin and lead that is used for a Schaffer mechanical pencil. The tool fits on a yard stick, but for the church window I milled my own lumber to hold it. I modified it by taking the lead out and replacing it with a finishing nail, sharpened on the end used to score repeatedly the rubber maid lid till it cut 1/2 way through, then it was scored from the other side till it caused the cut out to separate from the lid. The rubber maid material is easy to score like this - but if you try to use a drill, spade bit or hole saw it will fail, and rip the rubber. Test holes after each cut. I give the holes a light sanding to remove any left over from the cut.

I used a spade bit, the one that has tabs on the outer edge of the bit that cuts in about 1/32" almost the thickness of the material. The thickness is about 1/8" so if you cut a little from the front, then a little from the other side it will produce a perfect hole and not rip the container, setting you back a few bucks. Note: The first cut with the spade bit should be very gentle.

I have built 2 racks to hold the 8 rubber maid containers out of the 2 x 4-s ripped in half. I wanted the containers suspended so a little convex action on the bottom surface, to help with drainage - avoid stagnant water.

This is just a way I like to look at something I am building to get a mechanical view. It is hard to see the piping but the feed is 3/4" pex to a 3/4" x 1/2" x 1/2" tee to a 1/2" 90 degree elbow. So a 3/4" feeding 2 - 1/2" feeds, just for balance.

The blue steaks are drop controllers. I will be melting more holes in the green pot to encourage root development. On the right you see a 4" cube of rock wool supported by expanded clay pellets. There will be aeration system under the lid.

Installing the aeration system under the lids in the chamber of the roots, I did not want to use metal - In this system -- there will be no contact of metal to solution period... So I came up with a  push fitting using the plastic pex with pex pipe - these are very cheap for me so I use them.

First if you put a pex (from now on it is assumed plastic) fitting in to the pipe it is not very snug. So if you want it more snugger...lol... you will need to wrap it with Teflon tape - BUT if you push it in to pex pipe it rips the Teflon tape and the seal is compromised. So - use a means by which to camber or bevel the inside edge of the pex pipe, I use the the yellow reamer. I use the reamer to bevel the inside edge of the pipes to allow the Teflon taped fittings to insert in to the pex pipe with little damage to the seal. A little lubricant is ok like a very very very tiny amount twisted on to the fitting will encourage the seal but very very little is needed...It never hurts to expose the pipe to hot water to make it pliable.