Help putting old live rock back in tank..

N2Fan · 03/11/2016, 02:06 PM

Hey everyone, I have a quick question. Long time lurker and and about to re-do my rock scape..I took some old rock out of the tank a bit over a month ago and kept it in the garage, not thinking it'd be out of the tank long/not sure I'd put it back on but I want to add some back.

Not sure on the total weight but let's say the amount of rock I want to add is about 25-50% of the amount currently in the tank. I have ro/di water here in the house, if I'm adding that amount of rock, would it be okay to set it in some RO water, scrub it a little and add it to the tank? Basically what I'm asking is since its not all that much rock, maybe 15lbs and the tank has been basically FOWLR and stable for nearly 8 years(55gal bowfront), would the tank be ok if I added this rock, not worrying about curing it? Only a bit of CUC and a damsel and cardinal in there so there's not alot in there..sort of the beginning of working my fish tank into a reef.

Would this be ok?

Thanks reefers!

thegrun · 03/11/2016, 03:54 PM

When you start to add over 20% of your current rock's weight I would get nervous since the old rock will have some dried on organics that will start to decay once it is wet again with the potential to start a cycle and kill your livestock. I would either add the rock in at least two separate sequences with at least 10 days between additions or cycle the old rock in a separate container and then add it all at once.

03/11/2016, 02:06 PM	#1
N2Fan Registered Member Join Date: Mar 2016 Posts: 1	Help putting old live rock back in tank.. Hey everyone, I have a quick question. Long time lurker and and about to re-do my rock scape..I took some old rock out of the tank a bit over a month ago and kept it in the garage, not thinking it'd be out of the tank long/not sure I'd put it back on but I want to add some back. Not sure on the total weight but let's say the amount of rock I want to add is about 25-50% of the amount currently in the tank. I have ro/di water here in the house, if I'm adding that amount of rock, would it be okay to set it in some RO water, scrub it a little and add it to the tank? Basically what I'm asking is since its not all that much rock, maybe 15lbs and the tank has been basically FOWLR and stable for nearly 8 years(55gal bowfront), would the tank be ok if I added this rock, not worrying about curing it? Only a bit of CUC and a damsel and cardinal in there so there's not alot in there..sort of the beginning of working my fish tank into a reef. Would this be ok? Thanks reefers!

03/11/2016, 03:54 PM	#2
thegrun Registered Member Join Date: Dec 2008 Location: Garden Grove, Ca Posts: 17,023	When you start to add over 20% of your current rock's weight I would get nervous since the old rock will have some dried on organics that will start to decay once it is wet again with the potential to start a cycle and kill your livestock. I would either add the rock in at least two separate sequences with at least 10 days between additions or cycle the old rock in a separate container and then add it all at once.