Hello I am thinking about starting a 29 gallon goldfish tank. I would like at least 1 black moor goldfish. I know the rule is 20 gallons for the first then 10 more for each additional goldie. I hear that goldfish are actually schooling fish. And I know that 3 would be a school I guess but I can't keep 3 in this tank, but I would like him to have a friend so he doesn't grow lonely and that stuff. Plus I hear it's better if they are around other goldfish. Would two 10 gallon water changes a week allow me to keep 2 black moor goldfish? I can up the water change to two 15 gallons per week if need be.