I was originally suckered into buying your run of the mill gravel. Long story short I'm aqua scaping and have a densely planted tank already. I'm co2 injecting and have plant growth bulbs. I need to change out my substrate and I've got caribsea Eco complete ready to go. I've read a lot of conflicting information on whether to remove the fish or keep them in the tank. What is the best way to change substrate? My tank has cycled 20gal and I'm running a bio wheel 150 filter. I've got 6 neons, 4 platies and 3 guppies. I went with the Eco complete because it doesn't change ammonia or ph. My plan was to remove 70% of the water, and change out half the gravel and change. I've heard it can be very stessful for fish removing them or keeping them in.