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Cycling question


Mar 8, 2013
I've had my tank set up for ~2 months now, with 1-2 inches of argonite sand as a substrate and a marineland C-220 filter, which has a compartment for bioballs, but not a lot. I also have 1 piece of live rock, an artificial Tiki mask, and an artificial piece of driftwood. I have the latter two items in there just to give the damsels I put in there something to hide behind until I could get more live rock (The decorations and the damsels will be moved to another, smaller tank when the Octopus comes in). I have been testing my water two times a day since I've added the water and other stuff, and reached 0 ammonium and 0 nitrates/nitrites and those levels have stayed there for a full week now. My question is, will the tank still take as long as it normally does to cycle after I put in another 50 lbs. (50 gallon tank) of live rock? There are 6 damsels in the tank now, as well as some bristle worms from the live rock and some small snails from the live rock.


Staff member
Sep 4, 2006
Gainesville, GA
Anytime you put new live rock in a tank you will start an ammonia->nitrite->nitrate cycle. Aquarist often cycle new live rock in a separate tank to minimize impact. HOWEVER, for what you are trying to do, you won't have enough bacteria to handle the bio load of the octopus with your current set up and I would recommend putting the new rock in the tank to cycle AND removing the fish at the same time. Once you have a nice supply of cycled LR (rock that is loaded with bacteria and has been through the die off cycle), you are not likely to be able to catch the fish (especially damsels) without completely disrupting your tank. Once your tank is again stable, start adding animals that you need to feed to continue to build the bacteria that will be able to convert the octopus waste rapidly.

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