Greetings...i have outside ,flow-thgrough systems at work ,with varying degrees of shade cloth above them,all i have to do is add snails, Mithrax for Velonia outbreaks,Peppermint shrimp for Aiptasia.
Sound too good to be true....it is,...all of my animals do better indoor- in(CHILLED),closed system aquaria with MH+Florescent lighting,and synthetic sea salt.
I only use the outdoor raceways for corals that have settled on steel/rust,
(man-made structures).or have some other crazy invasive sponges or tunicates that must be removed before i bring them in.
-Dave
The day after hurricane Willma i found one of my raceways a block away(it had broken loose from it's plumbing and floated like a boat)..and it still had a few peices of coral in it(some survived)