I got my brother into the reefing world. I have a total of 170 gallon system and he wants to add a 40 gallon system in his room. When I perform a water change instead of dumping the water out can I add the water to his tank? I wouldnt fill his tank with 40 gallons of my water. Roughly 15 gallons maybe 20 at most. Would this work so he could skip the cycling stage since my water is already cycling and housing plenty of fish and coral? If its possible it will save him a month of waiting!
