Do I have to do a water change?


Reefing newb
I did water tests today with new Seifert tests today and all came out 0, (ammonia, nitrites, nitrates and phosphates). I read on another thread here that once you achieve that, you can do a water change and then add a fish to your tank. So, that being said, I have some, not a lot, of algae that's a little long for the snails...less than an inch, annoys me! Eventually I want to have one grazing fish such as a bristletooth for this. But it's too soon as I think that would be the last fish I'd add. Right?

Wanted to stay away from hermit crabs because I value my snails! I am thinking about an emerald crab...which I heard can take small fish once they get big enough. Has anyone ever gotten an emerald crab and then thrown it in the sump when it got too big?
Technically you could add fish now, but if I were you I would wait an additional week and do another water change, just to be safe. You cycled your tank right?