That is in general true, though there are some easier SPS out there. There are some low light corals for which multiple Fluval 2.0 would work, but it will limit your success and flexibility if you want to add things down the road, which you will! If you are fond of LED's, good options for lower-light LPS and softies would be perhaps 3x Kessil 360we on the 125 (assuming it is 6 foot long?) There are as many opinions as there are lights, so do your research. I'm planning a new 300gallon, for which I will use Kessils and T5 in combination, which will allow me to keep anything including SPS. If you start with Kessils, or some other LED's, you can add T5's later, or add additional LED units for higher light needs. EcoTech Radions are another good option that are an investment, but are adjustable and can grow with you. If you are just getting started, you might check out Bulk Reef Supply's YouTube channel, and watch all the BRS160 Episodes. This is a good primer, and will take you through setting up a similar sized tank - and everything you need to know. There series isn't done yet, but will get you pretty far into set up. There are like 5 episodes on lighting - a good watch.