The reactor being $33 isn't that bad of a deal... think about it, you would probably end up paying close to $20 for PVC
fittings and glues etc. anyway, plus your time. Although you could most likely build a much bigger filter without spending much more though. Anhow, the point is, its the dosing pump at $220 that kills.
In regards to powerhead and wavemaker... is there even a wave maker that allow you to set it to turn on for 1 second then turn off for X hours? I think most waive maker timer are based on minutes. So even if you set it at the minimum, at 1 minute with a small powerhead we would've likely still flushed the whole **** thing (unless its a 5 gallon bucket we are building)... now, if the unit CAN be flushed, then I could've just go back to my very original design and use X-10 timers (which I already have).