Refugium and sump design

That would work good i think.
Should keep anything out-- You just never know though. An astria snail can plug a pipe pretty quick! and with your water line being so hi up in the fuge you could loose some water until the sump is dry anyway.
In my eyeball tank I put in a 2'nd pipe just in case the first plugs up.

 

ok i gotcha, just sunk in. the "back-up" drain would be above the water line so nothing would be able to clog it and if the main overflow got stopped up the water level would raise to the back up. i could drain the back up higher then water level too. that way i would hear the "waterfall" into the sump so i would know something was wrong. if i did that i think i might go back to elevating the tank a little so the back up drain pipe would be even with the top edge of the sump.

 

Cool glad I could help
better to be safe then sorry

 

ok, something just popped into my head. both of the "feed" tubes for the fuge and the sump are going to be submerged under water. is there any possibility for a siphon from the fuge to the sump starting due to the difference in water levels??