Ive been working on a "drip" system also. Not so much of a drip really more automatic water change system. I am using an automatic sprinkler system to take care of draining and filling the sump on my tank. I have it worked in a proof of concept tote set up and it works good. At a certain time 2 valves open one to allow new water in through a house carbon filter system to remove chlorine and chloramines, that's going to add the fresh water right by return pump. In the filter chamber where water is drained to the sump the other valve opens to allow the excess water to leave the system. I was/am worried if one of the valves fail especially if the drain valve fails to open it'll overflow the system, so on the sump on actual install I will put a second emergency overflow above the valve operated one this one will be just open to allow sump to drain if water ever gets to high. Ill put it high enough so it doesn't drain anything in pump off situations. If power fails then no worries as water wont be added or deleted. I need to get a thermostatic mixing valve to adjust incoming water temp to 78 as this is going to change 50gpd in about 25 min. I used two 27g totes in my work up and it took about 45 min to fill both going through the filtration system. Don't worry I used most all that water for a water change, some had to go in the sump pit to prove it would work. (my wife was worried) ((not sure if that's what she was worried about or not but that's what I thought it was.....lol))
