Swords,
Firstly I thought of this myself and decided I would need some kind of filteration system. The gases that come off decomposing organics are terrible smelling and can be built up to problematic levels. To combat this I am gonna be using a carbon scrubber. The carbon scrubber takes air and forces it through several layers of activated carbon and UVC bulbs can be used further to "kill" the air. This I beleive is a starting point for clean air.
I then thought; How can I kick this whole thing into gear with its own cycle to really put an end to toxic buildup? Well, it seemed to me that I would need beneficial bacterias in the gravel to keep harmfuls at bay, I als would need a way for the soil to naturally breakdown without it becoming a nasty sledge. What better way to do this than with composting worms? So I have 3 worms that are 2" each in the tank, I assume they will breed and grow - I also am curious if their body size will vary according to them living in a smaller area. The flip side is that I must randomly add new organics to be eaten and broken down. The worms harbor extremely beneficial microbes in the digestive tracts that move to the surrounding soil as well, this will further aid in the cycle to prevent burn-out of my tank. The worms will need O2 replenished regularly and so is also a reason for moving air through the soil. Thirdly the moss should act as a minor filteration.
The nitrogen cycle has been put in place and has probably already multiplied. This was done with well established colonies from a 10+yr old fish tank, I watered every thing down a few times with water loosely run through the foam filter - which is where most of the bacterias are housed in an AQ.
Yes, I have 4or5 different kinds. One is white and flaky, one is blue/green and kinda bracket looking, another is red/brown and very spotty, another is very bright yellow and reminds me of piles of pollen, the last one is a sea green color and very pillowy and spongey. The lichens already began growth a few weeks ago but I have since collected local lichens and lichens from Puerto Rico and Florida. The lichens were crushed down to a powder and added to RO water and then sprayed onto surfaces with a regular spray bottle. Cheap spray bottles work best because they have a large opening, generally the fine mist sprayers are more expensive and the lichen dust would clog them. I am unsure of any specifics of the lichens in the tank but some have taken and hopefully more will. I will post new things and I plan to post photos but not until I have completed it which may be another month or so.
Finch,
Well, activated carbon is used to absorb smells in some cases but the problem with it just being thrown into a tank is that once they have absorbed to full capacity they then start to release back all that they have absorbed.
Joe