Pumpless DWC Circulation System

So,
theres three buckets-
One is the main reservoir, which is inside the tent.
the other two will be outside the tent with tubing ran inside to the main.
once a week, I will turn the valve to empty the main reservoir out into the bottom empty tote.
then turn those valves off, and refill the reservoir with the top tote full of pre treated water.
heres a pic: (READ) in the picture it shows the valve for the emptying tank at the bottom, it was a mistake, it will be at the top to prevent water from siphoning back.

What do you guys think?

i don't think you understand gravity properly

Sure i do.
if the main reservoir is higher than the emptying reservoir, it will work.

african american engineering at it's finest. no reason why it wouldn't work though as long as the main res is higher than the emptying res.. which is not how it's drawn but i got the point.

question is, is it worth all the hassle of two extra reservoirs and attention to proper pressure heads as opposed to just buying a 15$ pump

Even with a pump I'd still need to have at least the one extra reservoir. I suppose I could ditch the other and just empy it out through a pump and out through the window. I just cannot lift my main reservoir because it is extremely heavy. And after I do empty it, I would like to have another reservoir that has been prepared two days before so the chlorine and ph are all good.

So two reservoirs, and one pump to move water from the main and out the window. then i can keep my refill reservoir setup the same.