[scolley]

You can get a programmable timer ($20-$40) to do that. But I really have a hard time accepting the proposition that it matters. In fact, I have a hard time believing there is any difference between dosing every other day, and dosing daily.

Think about it. Let's say you target Nitrates to 14ppm. On a given day you dose so that it is right on 14ppm. Then two days later, it's fallen to 11 ppm, and you dose it right back to 14ppm. I cannot buy the concept that the swing back and forth between 14 and 11 matters to your plants. Both are enough, and not that far apart.

IMO you are barking up the wrong tree. If you see improvements when you dose manually, I think you have problems with your auto dosing amounts. Only rigorous testing and record keeping will answer this question for you.