well it chopped off a bit, but the upper left hand elbow is water from overflow into sump, the rest is self explanatory I think
The critical issue is space for drain down, the overflow box shouldnt allow much to drain off before it stops flowing because its below the overflow teeth, with a hole in the return line just below the surface, it should break siphon quickly and not let much back drain.
I dont recall the exact dimensions of a 10g, they are a little small in my opinion(used a 20L on my original 29g reef) but the divider is approx 2/3 the height of the tank, so I am guessing about 8"
If you set it up this way, as long as its flowing you will always have plenty of water to feed the skimmer. If for sum reason the overflow gets blocked or the U tube loses siphon, having a smaller
return pump chamber minimizes how much water can be pumped back into the tank, lessening the chance of a serious flood.
Also, as water evaporates off, the tank level and the first chamber in the sump will stay constant, the level in the return area is whats going to fluctuate, so this is a good spot to put a
float valve or switch for an auto top off setup, Hope this helps
