Upgrading to 170 FOWLR

[mangelo]

My question is can / should I use the water from my 75? It's very well established and thought that the new tank could benefit from the water and LR.

Thanks.

[sirreal63]

If your existing water is clean then I would use it and the existing live rock.

[disc1]

There's nothing in the water that is beneficial to you. All of the bacteria etc that you want to keep is on the rock. There's no harm in starting anew.

That being said, if it's clean then there's absolutely no harm in keeping it either. If you have fish that are moving too, they might appreciate the familiar water chemistry.

[bertoni]

I always used the old water. It's at the reasonable temperature, and it's cheap. :)