Not to repeat what others stated, but I think maybe the better question is (and we know you have a lot of phosphates or you wouldn't have cyano which is actually a bacteria) is what is their source?Low water flow is probably also to blame. Here's some thoughts:
1. It can be in the flood (flake is terrible) or;
2. the water (tap is loaded with them and using an old RO/DI unit with a worn out membrane) or some cheaper salt mixes are high in phosphates as well.
3. Try turning up your skimmer so it makes a wet skimmate instead of a dry foam.
4. Rinse your frozen food really well before feeding with old SW.
5. Try dialing back your lights a little (just a few hours will make a big difference).
6. Increase the amount and frequency of your water changes, and as a last resort;
7. Add a phosphate binder.
8. As you're already aware, change the bulbs.

If you're seeing negative effects to any corals or other inverst whenyou add the binder, then you should add less (only submerge half the bag), leave it in for a shorter period of time, or not at all. Good luck!