Covering soil for houseplants

Covering soil for houseplants

I thought someone here might be able to help with a houseplant question. In the past I've used spanish moss (the grey stuff, at the suggestion of a friend) to cover the soil of my houseplants, both to help them retain moisture and to look a little nicer. (I get sick of looking at the dirt.) But the moss gets kind of gross after a while and I noticed that some of my plants had little black bugs in them, which seemed to go away when I took off the moss. (Not sure what these were, they were about the size of a period, with no distinguishable legs.) Last week I repotted several of my plants, and last night I decided to try using pea gravel (at the suggestion of another friend) to cover the soil. I really like the way this looks, but is there any reason why this wouldn't be good for my plants? I have about twenty houseplants now and I would like them to remain healthy! Thanks in advance for your help.
The ‘after’ pictures (VERY picture heavy)

The ‘after’ pictures (VERY picture heavy)

More Pretties from the Guessing Garden

More Pretties from the Guessing Garden

My apartment

My apartment

garden boxes

garden boxes

new apartment.

new apartment.

Bottle brush tree

Bottle brush tree