but I got 3 months while this tanks cycles
Your tank shouldn't take longer than 9 weeks to cycle. The longest time I have ever seen is 9 weeks. Especially if you are doing a fishless cycle, your water should be inhabitable (zero ammonia and nitrites) within 4 to 6 weeks.
Anyway, you will love the saltwater aquarium. Live rock alone is enough to create an amazing underwater landscape flush with biodiversity. If you add corals and sponges to the mix, it just makes things more fun. Plus, SW fish are, in my humble opinion, so much cooler than FW.