Swamp water

hmm...
well just to throw ideas out there...
Get a spray bottle and put some future in it and mist it onto the foliage of your diorama, should put all sorts of shiny "rain" droplets.
For the swamp you could try future and take the foam from walmart that fake plants are put in, crumble it up and put it in patches (maybe after painting the foam) the foam should float in the future, even after being crumbled. It could represent algae and duckweed.
These are just ideas, I haven't tried any of them, so experiment.

Thanks for the idea!
-ERAD

Not a problem mi amigo!

For moss, you could dip a small sponge in paint. In small scales, it looks realistic. Also, for shallow water, you can use clear pouring resin with greenish brown paint in-between each layer of the resin.

Thank u very the tip!
-ERAD