This is the lid of my 1g Wal-Mart cracker jar. Drilled two holes, inserted two chunks of rigid, sealed with silicone:
Next I needed a way to secure the output so it didn't fall off and spew a gallon of RO on the desk/floor. So I made a little arch or bridge from acrylic scrap and superglued it on. The square is sized just smaller than silicone airline tubing, so it gently pinches it. This will keep it quite secure.
Next, I bent a piece of rigid by heating it with a lighter. With finesse, there's a fine line between softening and burning! It's also easier if you cut a piece longer than you need, bend in the middle, then cut the excess off one side.
And here it is installed. The output is still above the waterline, which is important.
I also made two very handy pico reef tools: a pico-size gravel vac, made from about a foot of rigid and a couple feet of normal tubing; and, an all-purpose tool made from a baby medicine syringe feeder measuring thingie, a little chunk of airline, and section of rigid just long enough to reach the sandbed. This is so handy -- you can use it to suck up unwanted items, blast sand off of LR, take samples of water for testing, and spot feed corals. Dunno how anyone keeps a pico without one! Well I guess a turkey baster works too, but this is a lot more slender and controllable IMHO.
The downer came when I tested the air pump with my reservoir. I scrapped the idea of building a stand, so now the tank will sit on the desk and the reservoir needs to go on the floor under my desk. The crummy little Wal-Mart air pump can only make 18" of head, tops, which ain't gonna cut it. So I definitely need a more powerful air pump, and will probably need to elevate my reservoir somehow so it's just below the desk and not all the way down on the floor.
Wish I would have just bought a Tom's Aqualifter, like everybody else smart, but I don't wanna wait for shipping now.