they are experimenting with LEDS right now and so far the tests seem promising.
i'm goin to run one solo on my 75g FW
tank. the figure out hte flaws from the early 90's and they work great
the one down side is YOU MUST clean it weekly while its not hard to clean you must do it.
for salt water they can save you a lot of money in skimmers and things like that
I have also found numorous reports of people experimenting and NEVER doing water changes, one guy had his SW
tank going for 12 months with not one water change and it look amazing, just toped off the evaporation
if you think about it, using an algae scubber is about as close as you can get to the ocean, algae clean the water in the ocean. other things do to but it has the largest part.
if the reason for water changes is nitrates the you'll never need an other water change.
his unit is pricey BUT everything is tops of the line and he can't mass produce them
once i have mine running i'll report back results.