Well, I personally like the mixture of 10k and 20k so maybe two more fixtures to allow you to stagger your lighting (10k 20k 10k 20k). As for the brown algae... just a part of the cycling... be sure to continually run your carbon, leave the lights off, and top-off your water with RO(reverse osmosis) water. I would also suggest feeding very lightly if at all and begin getting your sump/refugium designed(in place of the canister filter) along with a skimmer. Now, I am a firm believer in skimming... it happens naturally(those nasty bubbles and foam you see after high tide and after storms, drying on the beach) and it also acts as a very dependable set of shocks on a car... the car may run as smoothly as possible, but those shocks sure take the punch out of those bumps or potholes. Anyways, let patience be your best friend fot the next little while and take thing slowly so as not to kill your desire to go completely and long-term with captive reefing(not just our site LOL). If you are happy with your lighting, try going with the low-light species... like shrooms, deeper water leathers, softies, etc. You already have a decent kelvin temp with the 10k. Maybe, stay with that 10k and replace the other with a 20k. Make sure to keep up on your lighting... replace those bulbs, at least, yearly as their color shifts as they get older and can begin to offer a better light color for the algaes than the corals without you even noticing the difference.

Jason