Well I've been reading about this and finally decided to try it. This involves using Calcium Bentonite powder (from brickyards) or Sodium Bentonite (all natural kitty litter) mixed with water and sphagnum peat moss to make a thick mud spackle that goes on the tank wall and is kept wet. Plant's root in it, moss grows on it and it wicks water up from the bottom of the tank soil helping keep the whole tank humid.
That's the theory anyway. I have seen wonderful photo evidence of this being awesome so I thought I'd like to try it as I'm tired of the spray foam and silicone which is very hard to keep wet enough for moss growth without an automatic misting system. This method is WAY cheaper than foam and silicone and is all organic and that's a plus, so here we go...
I looked at Home Depot, they don't have Calcium Bentonite powder, you can get it at brick yards and pool places but I didn't have time to find one today. However, Sodium bentonite used in all natural clay kitty litter is almost the same according to those who have gone this way before me. I am using the $2.26 unscented/natural bag from Wal Mart. Some have even mixed some reptocal powder into the kitty litter to give it a bit of calcium.
Here is the back of the bag. I think the scented stuff is in a blue bag IIRC.
Boil a gallon of water and dump 3/4 of it into 3 quarts of clay and wait a while for it to soak up the hot water and soften. Then using a Jiffy Mixer on your power drill ($9 at Home depot in the cement dept) mix it up until it becomes smooth and then keep beating it until it becomes like cake frosting. You may have to add more water.
Now dump in 3 quarts of sphagnum peat moss and the last quart of water and mix again.
You're done when you can grab a wad of it and open your hand upside down and it won't fall, if it's too wet add another handful of peatmoss and mix again. You can do all the mixing of clay and water and peat by hand, it's just so easy to use a jiffy mixer that if you have a drill no sense wearing yourself out.
Now you just take that thick mud and squish it onto the back glass and make sure it's packed tight, you can sculpt planter bowls and ledges in it. It sticks as long as it stays moist it cracks and falls off if you let it dry out so no good for desert setups. Use that Floor Patch product and sand I showed a while back for dry setups that won't crumble when dry.
If you want to add driftwood just poke it in and pack some mud on it and smooth it down This will easily hold a dart frog, insect, or small lizard (anole, small gecko sp.) but not snakes or iguanas! LOL
The water portion is Flourite clay gravel, the drainage layer on the swampy land portion is Hydroton clay balls (Petsmart sells it now but for a whole lot of money)
I used peat & cypress mulch for the planted portion, some people even use the clay background mud as a soil but I'm not so sure about that yet, I'll try it on a small nano tank scale first
I've embedded java moss all over the background and made a little riccia patch across the water line. The tank will be misted 1 - 2 times a day along with the others so we'll see how it goes.
I will be adding more plants of course but I've slashed my leg open on a pile of glass I cut for my 6 nano vivariums so I'm done for the moment keeping my leg elevated hoping I won't need stitches! LOL