Lifetime of Live Rock

[robert]

But, if you read this article written by PaulB, he says:

There is one more non-typical thing that I do that some may consider either risky or just useless. I mentioned above that I add bacteria from the sea to my tank. I feel bacteria are the most overlooked aspect of this hobby, and are vital to a healthy, long-lived tank. Bacteria cover everything in our tanks, but are they the correct bacteria for our purposes? Probably not. Bacteria enter our tanks in a number of various ways. Every time we put our hands into the water, we add bacteria. When we add fish, corals, rock or food, we add bacteria. The bacteria on the rocks and fish were at one time in the sea and “some” of those bacteria are the correct bacteria for our needs. But eventually, that bacteria will stop reproducing and will be outnumbered or outcompeted by other bacteria that may not be dangerous but do not necessarily help complete the nitrogen cycle. Why do so many people change so much water and still have nitrates? If we had the correct numbers and types of bacteria, we would never have to change water just to lower nitrates; the bacteria do that for us for free. I have found that by adding bacteria from the sea a few times a year, my reef stays healthy. I have no scientific data on this theory, but I do have a 40-year-old tank with an undergravel filter and no nitrates.

That might provide explanation why some tanks crash all of the sudden after many years of successful operation. Clogging by detritus and/or algae might not be really a problem. Killing of beneficial bacteria and bringing system to "Day 1" of cycle definitely would be a problem. Anyway, just another angle to look at this.