Reefman97
Aquarium Advice Activist
- Joined
- Nov 3, 2012
- Messages
- 111
If I do a 50% water change will I start a new cycle?
No, the bacteria is in the sand and rock, not the water. But you can shock fish and corals with that large of a water change, say if there is a temp difference or salt level difference. Why do you want to do such a large one?
Here is what happened to the sand I moved and why I got all new. See all the black, that is all dead stuff ready to release toxins into the tank.