Ues, yes and yes. I have one rock with quite a bit of interesting algae, and a few patches here and there. Only have 1 emerald and one snail in an almost 600 litre system though...
And they alao have the ability to trap detrtus from which they harvest nutrients befor it even gets to the water...
And they alao have the ability to trap detrtus from which they harvest nutrients befor it even gets to the water...