Water cycling

[seapony]

Any benifit in adding water from an existing 55 gal tank to a 15 gal tank my son is cycling we are in the second week of the cycle

[reefrunner69]

IMO, very little. I like to use the water from an existing tank to set up qurantine tanks and to do water change on q-tanks, but there is very little beneficial bacteria free floating in the water. The nitrifying bacteria colonize on surfaces, most abundantly on surfaces with lots of oxygenated waterflow. It woould do alot more for a boost to take a cup or two of sand and add it to the tank than the water