What’s the easiest vs the hardest corals you’ve ever kept? To me, every coral is difficult even the easiest ones on the market. I need some future addition ideas. I find the encrusting corals to be one of the hardest (and coolest).
It depends on how much you are willing to spend and how much time you can put in. For example if you spend 30 mins per week on your tank and don't want to spend money on dosers/good lighting, acros might not be the best option.
If you can test your tank 1-2x per week and have dosers+good lighting and are on top or nutrients + water changes every 1-4 weeks you can do the more "challenging" corals. Things like Acros, Torches, Gonis, Most sps etc.
If you can test every 1-2 weeks and dose by hand 1-2 times per week + water changes every 1-2 months you can do most lps + hammers, chalices, stylophoras, montis, frogspawn, acans, pretty much all soft corals, etc.
If you want to test, water change and dose whenever you feel like just stick with soft corals.
In my experience all of the corals I've kept from zoas to acros are pretty low effort because of automation and scheduled routine. It all depends on what you are willing to do. I'm not sure the exact situation in your tank but do research on your corals and stop "leveling up" the corals when it doesn't fit your lifestyle.
In my opinion a mixed reef with branching sps, torches and coral gardens is the coolest.
I would recommend slowly improving the conditions in your tank and adding harder and harder corals over time.
Good luck :)
I do not recommend this frag for anyone unless they have a very established system with strong track record of growing SPS. I have learned my lesson the hard way.
