Starting a saltwater tank

[Aikidoka]

Guys,

I'm thinking of switching my 125g into a saltwater tank, is it hard to maintain? Especially for a big tank and a beginner as me? I've been an aquarist for so long, keeping fish is not new to me, just saltwater.

So, do you recommend it? Or go for a smaller one first then jump to big setup?

Any inputs will be noted. If you ahave any tips for me please put it here, thanks!