Lack of algae

[sunce_22]

So i have had my 20G reef tank set up for about 3.5 months now and I have nearly no algea growing in it. There is coraline algae growing on the glass, and a couple spots of green algae, but they are so small they are basically invisible.

Does this mean that my tank is healthy or unhealthy? I keep reading of people battling algae, and I'm wondering if its a good thing that I'm not.

I have 20 hermit crabs in the tank and ONE margarita snail (and Im sure she can't be eating that much!)

Is it healthy to have no algae?