Well Michael here you are at last! Welcome to the forums and thanks for joining! Regarding terrarium culture, my recommendations are to grow the plants in indicidual pots in the terrarium, vs. trying to do this in a "substrate" terrarium where the plants are planted directly in the medium. The former method allows for greater variation in substrates, and if problems arise they can be individually dealt with. Substrate terraria are pretty, but in time they become unstable for various reasons.
If you are getting lots of algae, mold, and moss growing in your pots it is likely due to trace nutrients in the peat and sand that you use. I always rinse my sand (pure white silica) until the water runs clear. I would do the same with the peat if I had a way. The way I handle this is to keep some peat outside where the rain runs through it. Old peat is better for CP, and the natural leaching action of the rain usually keeps these incidents to a minimum.
Once the plants have germinated and have some root, I sometimes spray the surface if I see the green goo starting. repeated spraying can leach away the nutrients, but this is not always successful. Prevention is the better method.
As to the moistness, I generally grow most of my tropicals in tray watering, using only rain or distilled water, and I change the trays when algae becomes evident (It needs doing now, but I have been to busy to get to the chore!
I hope this helps you.
