i dont think so, water usually gets very dirty as the old substrate is removed. also theres some form of gas under the substrate which is toxic to fish, because of the inevitable anaerobic conditions down there.

place fish safely in another tank, before doing that operation, also water would have to be replaced.

take care.
"James" wrote in message news hello all,
I have a 46 gallon bowfront freshwater tank with live plants and approx. 27 fish, ranging from angelfish to cardinal tetra's. I was thinking about replacing or adding some Eco-Complete Planted Aquarium Substrate from caribsea to help my plants grow, in addition I think it would look nice as well. can I take all my plants out and put in this new substrate without removing my fish? I wouldn't want anything to happen to my fish.

what do you think?

Thanks,
James