[dennis]

I dose Flourish and Fe gluconate at 1ml per gallon per week. Yup, its a lot but the growth is good and I have no fish or inverts issues. So, since it has to happen daily, 60ml total for 7 days is 8.6ml daily for micros. Macros I could mix to get the dose right but I was hoping for a fool proof, easy to use and accurate- oh and really cheap- method of autodosing.

My current test setup in the laundry room seems to give about 47ml per 1/2hour cycle. This may change a little if it is moved to the tank if hose length or head heights change. This also uses 18" of airline tubing in the bottom of my container for the initial dose, which is about 7ml if the tubing is full. I've tried all manner of hole sizes and check valve configurations, all yield similar situations, an eventual venturi that spits. I may try modifying the timer I have so that the actuator is narrower, thereby letting the power be on for a shorter period of time. I am sure I could get it down to only 5-10 minutes of run time this way.

The next option is something like magicmagnani's air doser but I don't like the variation in dose size over time, nor have I been able to control it to dose less than several hundred ml in 1 minute.

Bahhh!

Thanks for the tip on cheap timers. I remember seeing some digital ones at Walmart but did not look closely at the time. Now I just need an excuse to go back there.