A 290? I assume you have a sump and plenty of space underneath the tank? Research and build yourself an algae scrubber. You would be amazed how well it will pull out nutrients from the water. It grows algae on the screen, and removes algae from the tank.
A 290 tall has issues with not getting enough flow. You should seriously consider adding a lot more flow to the tank. More then what you think is necessary. That will greatly help with algae issues.
Here's a one-two-three punch that will remove hair algae / cyano from your tank in a month:
1. Research and build a properly maintained algae scrubber. This is the ABSOLUTE MOST IMPORTANT STEP.
2. Increase the amount of flow. A 290g tank should have 30x the amount of turnover, not including the flow coming from your return pump. That's about 9,000gph of turnover from powerheads alone. It's a bit daunting, I know. But, it will go a long way for the health of your corals, fish, and live rock. Koralias make decent powerheads, but if you have the money, I'm sure someone is going to recommend to get Vortech powerheads. lol
3. Let your algae scrubber run for two weeks prior to this: Kill your lights for 3 days, then turn them on for 3 hours a day for 7 days, 5 hours a day for the next two weeks and then the full 8 hours when you start to see most of the algae dying away. The corals shouldn't be effected at all if they are being fed. By turning off the lights in the display and letting the algae scrubber run wild for a few weeks, It will pull out most of the nitrate and phosphate in your tank. Just keep running it and you will notice a MAJOR difference.
I got rid of the hair algae in my 20g in two weeks with this method. It will work on a more grand scale too. I got rid of hair algae and cyano in a 110g tank in less than one month also with this method. I have experience with it, that's why I recommend it. It's the all natural way to do it.
