So I have a 100g tank thats cycled, many
fishies, a some softies and I've decided to also started a 29 gallon tank since i have all the equip i need... I was curious if i could just start this tank by using 20 gallons from the 100g tanks water change. also stealing some rock and sand from it. So basically i would be looking at 20g of old and 15 of new water to go into the tank initially(...