SMW945
Member
I currently have a soil substrate topped off with gravel which does need replacing from a plant nutrition point of view, and I wish to just have a Tropica soil only substrate in order to plant delicate rooted carpeting plants. My thought process is to remove the fish temporarily with the filter/heater etc, in existing tank water. Once I have replaced the substrate and replanted, would I have to go through a period of cycling the tank for the fish or can you place them straight back in as long as I use previous tank water and the already previously used filter? I’m assuming that the new substrate would possibly leak some toxins?