I have three shrooms with same pattern (blue with orange outter rings) and love them with moon lights only....mine have gotten huge and look like one is going to divide soon. If not one is going under the knife soon...lol I don't know how long it takes. I am sure it depends on lights, water flow, water conditions etc. so it will vary between reefers. I will be interested to see how long others feel it takes. I have only had ricordeas for about 9 months...