I'm going to do start an experiment with auto dosing this week. I'm going to use the Fish Mate automatic fish feeder:
to dose my macros dry and an Eheim Liquidoser to dose my Excel and Tropica Master Grow trace fertilizer. It seems like the cheapest, simplest way for me to set up automated dosing. $55 for the liquidoser and $30 for the Fish Mate. Any feedback appreciated and I'll update with how it goes.