24G DX ATO & Dose

Been working on a combo ATO & Dose set-up for my 24g NanoCube DX. This is the way it works:

ATO: During the day, if the float switch closes the peristaltic pump turns on and pumps FW to the tank. Normal ATO stuff.

Dose: At midnight a relay on a timer closes and cuts the float switch out of the circuit and energises the same pump as before. This time the valve for the TO bottle is closed and the Kalk dose bottle is open. The timer runs the pump for 15 minutes then the relay is turned off and the system goes back to the ATO configuration.

The pump is powered by a 8.4vdc cell phone charger. The relay is a Radio Shack 120vac #275-217. (The PC Power supply in the one pic is for powering some fans and moonlight LED's .)

Right now I have to manually close and open the valves on the 2 bottles but one of these days I'll find the right solenoid valve to make it fully automatic. I also plan on mounting everything in a box to clean up the area.

Pics:

And this is the tank at 2 months.