I will retire the 29 gallon as soon as I get the 40B going. With my freshwater tank and the 20L experiment tank this will be more than enough to keep me busy... lol... I'm going to order more BRS dry rock and Dr. Tim's for the 40B. I like how the rock looks better that the live rock I have in the 29. Once the rock in the 20L cycles I will transfer that to the 40B with the new dry rock and then put the rock in the 29 in the 20L. How many of the Rapidled Par 38's would you put on the 40B. I was thinking 3.