Step 3: Put it together
Basically, you want the growbed, filled with gravel to sit partially above your fish. For 15 minutes, the pump pushes water above the tank and into the grow bed. The grow bed has holes on the bottom corner that sits above the fish tank, emptying back into the tank.
We achieve this by using the Dremel to drill 16 1/16" holes about 1/2" apart on the bottom of the under-bed tote(grow bed). We also drill 8 1/4" holes near the top of the grow-bed to save overfilling the bed and flooding the living room! Hold the Dremel in a way that you are drilling from the middle of side that is over the fish tank, if you drill from the center the water will pour out of the grow bed towards the middle, also saving you from flooding. Also, drill at least 4 1/8" holes on the upper rim of both sides that are perpendicular to the side over the tank, directly across from each other; these will help secure the tubing later.
Place the roughtote on the floor, next to the stand that holds the grow bed and fill it partially with water. Hook the tubing up to the water pump and place the pump inside the tank, with the other end of the tubing securely in the grow bed. Make sure the grow bed is hanging over the tank in a way that the water will empty back into the tank, and plug-in the pump. Adjust the pump's control valve to slow water uptake as necessary. When you think you've got it close to perfect (water rises in the grow bed to the 1/4" holes, but not past), unplug the pump.
Fill the 2L bottle with water and cap it; place this on the side of the grow bed where the drainage holes are drilled. Then fill the grow bed with your washed (and re-washed:) gravel. The bottle is there to protect your drainage holes from the root structures of the plants you'll be growing. Those roots will plug the holes and you'll have another potential flood in the room.
Place tubing over the gravel. Using the scissors, cut the tubing at the far end of the grow bed and use the end cap to, uh, cap it. Drill 5 or 6 1/8" holes all the way through the tubing, spaced along the length of the tube. Using the twine (will eventually rot, break, and need replacing), tie-down the tubing so that it doesn't move when there is water pressure.
Time to test the pressure on that pump again. Adjust it as necessary.
Take the lid from the roughtote and cut enough space out of it to allow your water to fall through, but retain the handles and connect the lid to the roughtote for extra support. I also use the cut-out portion laid across the top as a splash guard.
Congratulations! You're done with the construction part of this "ible."
However, DO NOT PUT FISH IN IT YET!!! Doing so will almost certainly kill them.
Next step will get into some specifics on how this whole thing works...