Old vs new water for QT

[Steve1500]

Hello, my DT is nitro cycling right now and I am thinking about setting up my QT. Which is better to use in the new QT: Use the DT cycled water (once it's complete) but before I put anything in it (only live rock/live sand in it right now) or start with brand new uncycled salt water?

Pros/cons?

Danke,
Steve

 

[Fishfinder]

I use water from my DT just because that makes me do a water change

 

[Smo]

Use DT water if you trust your live rock/live sand (i.e., did it come wet from a LFS?). Otherwise better to wait at least 76 days of fallow to ensure no parasites that could infect your fish.

 

[divewsharks]

Hello, my DT is nitro cycling right now and I am thinking about setting up my QT. Which is better to use in the new QT: Use the DT cycled water (once it's complete) but before I put anything in it (only live rock/live sand in it right now) or start with brand new uncycled salt water?

Pros/cons?

Danke,
Steve

Won't much matter, the water does not hold enough nitrifying bacteria. The bacteria colonize the surfaces in the tank, rock and sand. If you intend to have a QT tank, begin cycling it now as well with fresh water. Alternatively you can put sponge or other media in the sump of your main tank so that those items are colonized by the bacteria and can then be moved to the QT tank when you get new fish.
If you do this, DO NOT then put the sponge/media back into the main tank -- its a one way trip.