We grow lbs of it weekly. There are some secrets to growing but also its not that hard to figure out. :) Light (high powered full spectrum LED, one that can grow veggies-- hint hint. ), then comes nutrients. You will want to keep mag/calc at bay (never too high) and nitrates not too high but high enough for the chaeto to thrive. Phosphates are also important but again not too high and never zero. Lastly, Iron and ammonia are important too, dont let those deplete, yes zero ammonia is not as good as the test strips have you think it is. Iron is hard to test for so most just dose a little monthly to ensure there is some and/or do regular water changes.
Dont get hung up on trying to get the chaeto to spin or roll, it wants light and oxygen, so just flip it around once in a while. Again, we grow a lot of it and the last 10 years we have learned a lesson or two. Once you stablize your system and know what your system needs to have dosed weekly/monthly you will end up harvesting and throwing some away. :)