Like I said before, I'd stay away from BPs unless you are shooting for ULNS for SPS, or have major algae or nitrate issues. I would consider it only as an expert level system, even though the concept seems simple. You need to watch the tank light a hawk when everything is adjusting. If you use them, you must be prepared to:
- Keep and maintain your Alk. below 8.5 or less.
- Actively feed your fish and corals A LOT more than before once they kick in. I now feed my SPS every day and fish 2x a day, and put extra in on purpose.
- Adjust your lighting schedule and/or intensity down when your tank reaches (ULNS) to avoid light shock
- Weekly water changes to keep up with trace element consumption (or separate supplementation if you have the time/patience to test)
Not doing any one of these things can cause a tank crash, and if more than one of these conditions is not adjusted you're almost assured a very bad experience. I was approaching a crash before I started really paying attention and making corrections for the four points above.
So overall I agree with the Beard!