Substrates that provide nutrients are typically a non issue. Some of the plant substrates (I believe the ada among others) will leech ammonia initially. With some planning, you can avoid issue. For an example, I have a 10g tank at 4+wpg with 2-3" of high humus topsoil covered with 2-3" of pea gravel that grows anacharis, corkscrew val, and algea very quickly. I throw cuttings from both into lower light, inert substrate tanks with some success. Both types do better in a 55 with an 80watt shoplight at 6500k. The amount, and temperature of light matter quite a bit for plants (And algea. Expect to have a bit of both) Your best bet may be duckweed - Common Duckweed, Lesser Duckweed, Lemna minor(resembles tiny lily pads ~1/4" across ) . Many aquarists hate it, but supposedly goldfish/koi/omnivores love it. Odds are you can get enough to seed the tank for free (It won't take much at all, and is near impossible to get rid of - just a heads up come transfer time ;) ) It's a small floating plant that grows beyond fast with good conditions. Being on the surface allows it to utilize much more light from your fixture (PAR values drop fast as you go deeper into water). Might be worth checking into. 1 small duckweed lily is capable of reproducing, so odds are your lfs wouldn't bother charging more than a buck or two for a whole bag. (Read, I've known people to dislike it that much. They'd be scooping it out weekly because they had fish that ignored it for tastier foods - though the dangling roots are great for fry) Hope it helps. ^_^

In as word : no. Vegetables need mucho mucho light. There should be -- at a minimum -- two 40-watt florescent lights, 48" long, suspended a few inches above the seedlings, moved up as the seedlings grow. Cabbages probably want to be grown as cool as possible, as well. A cool sunny window with a supplementary 100 watt incandescent (or the equivalent) in the evening would probably work also. My mother grew delphinium seedlings that way years and years ago in the old days before we had all this equipment at our disposal. I am not an expert vegetable gardener, but I imagine you would want to get those cabbages outside into the ground as soon as you ever possibly can. They are winter vegetables, no? The good news is that seeds are cheap and you can always try try again.

***Update*** Sorry I haven't come back to this thread for a while. It is a long story what all has happened that involves nearly dieing, months of physical therapy and a surgery. Like I said it is a long story.lol I ended up coming up with a top for my terrarium. I used wood that I cut to fit and plastic. I cut out an edge around the piece of wood so it wouldn't shift and fall in then I attached plastic to the underside so the wood would not warp. I was able to attach my light fixture to the underside of the lid. Both plants and cats seem to be happy and safe with this solution. Now all I have to do is redesign my pond so it will hold water. Thanks everyone for the ideas. Foxy.

hi Generally I've found that tropicals are easiest to maintain, they appreciate the high humidity.low light conditions . There are many ways of setting them up mostly varying by how much water they contain. You can have waterfalls,streams , even combine aquarium / terrariums called paludariums. the latter are my favorites combining submerged with emergent foliage and epiphytes in the upper portions . Of course if you keep animals you'll need to design it around their needs . Of course these can be brackish as well as salt water with different plants and animals of course I'd choose a theme based on the environment you'd most like to represent . Desert terrariums are possible but I found them very difficult to maintain ,though with the right equipment it can be done!! good luck gary