Spent most of today on DIY projects for my tanks, great fun, but doesn't happen often...
First improved the DIY filter in my 43 gal tank... it's a "Mattenfilter" with two Filstar foam pads squeezed into a tank corner. Got a slightly stronger pump, and included an internal inline CO2 reactor which replaced the unsightly ladder.
Then I replaced the outflow for my filstar with a selfmade plastic pipe thing. I bent 3/4" pvc pipe using a metal spring inside, heated the pipe up over a gas stove burner, and got a nice narrow U-turn that just so fits over the tank rim. Heated up the end and pushed a short piece of 1/2" pipe into the 3/4" pipe, which fits the Filstar 5/8 hoses, and secured the filter tubing with one of those wonderful green hose clamps from the garden department.
Finally, used the little pump leftover from the filter upgrade, and built an auto-doser. Took a gallon can (used for milk/juice), cut it a little so the tiny powerhead (AS606) would fit in. Used some tubing to connect it to an airline, and added inline a little drip "T" with an open end. This reduces the pump pressure, and the open end will provide for great mixing while the pump is running. Just need to play around with a timer and see how much I want to pump in a minute, how many days this will last, and how much fertilizer I need to add. It will keep my 100 gal tank topped off too. I plan on getting about 2 weeks out of it. Easily adjustable, just takes some testing.
Okay, where's the timer?