I would get your water going so you can start your cycle. There is debate as to whether you should run a protein skimmer while cycling. On one hand, some say that you are removing wastes that your bacteria feeds on which helps it to multiply etc. The other side says it will cut down on algae growth due to the nutrients and waste as brown algae thrives on that as well especially since you aren't doing water changes just topping off with RO
water. Are you doing a fish less cycle?