Does live rock have a life span?
 

In such a confined space as our tanks I start to wonder if live rock eventually is reduced in its filtering capabilities as time goes along and becomes nothing more than base rock. Has anyone had experiences or observed changes in their live rock and began to wonder how 'alive' it still is?

I believe it does have a lifespan, but it will vary widely based on the tank it's in. Detritus buildup, nutrient adsorption and general clogging of the pores by dead bacteria will impact it's ability to filter. How long this takes, who knows!

A while back I thought I read on here rock should be replaced at 10 years. And if my memory serves me right (however highly doubtful) was it not you Brad that brought this up?

I may have brought up replacing, but not at any given time frame. I've seen tanks turn to sewage at 4 years, and tanks still running well after 10..

I was just reading a thread on RC about a 40yr. old reef tank...it's more than 200 pages starting back in 2006ish, I haven't come across anything where he mentions any rock change. I have read other threads where people talk about "recharging LR" or "cooking LR" every 5 years or so...I've cooked rock myself, it really sheds allot of debris after a few months.

I agree with Brad but to add to the thoughts I think it's possible to somewhat "renew" rock by "cooking" the rock (by "cooking" I mean sit in a livestock-less but still seawater environment and not "place the rock in a pot and put it on the stove" .. I've never really liked the term "cooking" for live rock because of that imagery). After cooking for a few months a lot of the initial critters will need to be reseeded though.

In my own experience using rock that had been dried and left outside for a period of time, that rock was nowhere near as effective in maintaining a healthy reef as fresh rock would have been. It does the job but it took much, much longer for this tank to establish itself and hit a healthy groove. And at that, I have to be much more aggressive with nutrient management than I have with previous tanks. So I am totally convinced that live rock can have an effective lifespan. At least with cooking it though it can be salvaged as I think it's a total shame to see rock end up in the garden just because it hit "X" number of years old..

http://www.reefsanctuary.com/forums/...ck-anyway.html

quote: some aquarists claim that live rock should be replaced every 5 to 10 years. The lifeforms inside the rock will die off of their own accord, and the help the live rock gave at removing nitrates will diminish as the rock ages. Some claim that once coralline algae covers over the crevices and these worm holes, that the rock will loose its ability to handle nitrates, too.


Good read... anyways

This is what I was talking about...told you my memory was bad.

P.S. I have a good memory just not a long one. :wink:

I can tell you from first hand experience there is an "expiry" date on your rock and I definitely noticed it when my system hit is threshold for nutrient export. Granted at the time it was really difficult to see and pinpoint, but in hindsight and after having made numerous unsuccessful changes before swapping out my rock.

I plan to rotate pieces in and out of my new tank to try and address this long term, plus teaming this up with aggressive alternative nutrient exporters, skimmer, media, filter socks, etc.