Thanks for all of the input, guys! Now, to reply all of your inputs:
The fuge will be directly under the stand, and all designs I've seen have lowering level from water input towards the output. Only the water level in the last chamber, the sump, will constantly vary due to evaporation.
The reason the sump is so large is to allow more room for evaporation, and therefore longer intervals between the required fresh water top offs. I'm sometimes away from home for a few days, so a larger sump works better. I'm also going to be running a DSB
in the main tank, so fuge size and bio filitration in it aren't so critical. The main purpose of the fuge is for aestetics in the main tank. One corner overflow and a few return water jets just slightly poking in at the water line, will be the only clutter in the main tank. The fuge will keep powerheads, heaters, etc out of sight. The secondary purpose of the fuge is to house critters unfit for the main tank, and to harvest some macro algae for the tangs to much on. Unlike reef tanks, FOWLR
tanks aren't as senstive to the larger changes in salinity resulting from less frequent and therefore larger fresh water top offs, so I have and can get away with this. I also plan on running a 500 water heater, which is prettly long, in the sump area.
The third and fifth baffles, located from the left, are to catch and contain the micro bubbles coming from the previous chambers. The skimmer plus the waterfall from the fuge to the sump will make alot of bubbles. The bubble containment baffles should hopefully catch the bubbles within, allowing them to surface and diffuse, insteading of passing on.
in the skimmer chamber is a great idea, and I now plan on using it. The bottom of the skimmer will be on a stand, several inches from the bottom of the 40. This leaves plenty of room for rock. The skimmer output will also generate highly oxygenated water for the bacteria on the rock to thrive, another bonus. Again, excellent idea and thanks.
Everything will be contained within the 40, for sake of simplicity, and less chance of leaks.