well, we had a catfish (matthew) and the goldfish (bob) in a fairly decent sized tank when we got them. as months passed they grew larger (obviously) and so we had to move them to a bigger tank. the tank was glass and we got it from someone we sorta knew, they had lots in their shed. so we put them in and the night we put them in, CRACK, the tank cracked and all the water and fish went gushing down the floor. so the only other tank we had was the old one so that was going to be their temporary housing. so we were left with a descent sized catfish and goldfish. he (the goldfish) was now at least 30cm (we measured him when he was next to the glass). so we decided to let them go to a new home and gave them to a pet shop. the catfish was sold fairly quickly for about ten bucks. it took about a week before the goldfish was sold-someone payed $25!!!!!!! and that's the end of the story.