Don't think I've ever seen one at 9 cm, usually chilling around the 5 cm mark. Great fish, easiest way to keep them is with them as the dominant fish in the tank. They don't handle other dominant fish well at all.
i have 2 in a 75 gallon and they are always coming down with ick. My water test perfect I do weekly 40% wc. No other fish in the tank has ever come down with ick. Will not be replacing them with more golden rams.
I have four in 40 gallon with lots of plants. They can be a little shy and hide when walking in front of the tank. No problem with food will eat most anything. I hope to get at least one pair and would love to see fry.