Dumb Q about starting tank with established rock & sand.

[ocean_lightning]

I'm planning on buying a used setup from a guy on Craigslist. The tank had been set up a while, it was well-established when he took it down. The rock and sand he kept in saltwater to preserve all the nitrifying bacteria and other life. My question is, since they already have established colonies of these bacteria, would the tank still cycle in the traditional way if I add them to the tank with new water? I realize this is probably a dumb question to ask here, especially from one who has kept a saltwater tank before, but I'm just not sure why the tank would start going through a cycle to build up these bacteria when they're already present -- why would there be a build up of ammonia in the first place? I realize adding live rock alone initiates a cycle, but if it's from an established tank I was a bit unsure if it would still have the same effect. Then again, isn't all live rock, by definition, established? I still don't think I would be able to add fish right away.

Thanks lots,
Jesse

 

[Civicdemon]

You will mostlikely still have a cycle. But it could just be shorter and go by fasyer than usual. A couple things that will affect the outcome would be how he kept the rock alive ? Did he use a heater and powerhead ?? If not there could be die of from the water being to hot or cold and missing oxigen.

 

[Marinne13]

also, if you are reusing that sand and it gets stirred around this will cause a spike

 

[ErinCahir]

+1 to both.

You may or may not still have a cycle. Don't reuse the old sand.

Once you get everything set up throw a piece of raw shrimp in and monitor for ammonia. If you don't see a spike, you skipped your cycle and can add your first fish.