Finally finished! I had an extra Zoo Med 12x12x12 tank and decided to build a planted terrarium. I got the idea from here : Mossy Vivarium - Frogforum.net


Here is a rundown of the supplies used:
Tank
Zoo Med Micro pump
Forest Bedding (one brick - expanded and completely dried, any moisture and it wont stick)
Great Stuff foam (one can - I used the type for large gaps)
GE Silicone II caulk - brown (two large tubes)
caulk gun
Egg Crate/Light Diffuser
Gorilla super glue
Small Jiffy Pots (bio-degradable seed starting pots @ Home Depot)
fake plants (stripped off the leaves to uses as roots)
small zip ties
small wire cutters (works great to cut the egg crate)
a variety of rocks of different sizes
sand (I had large grain sand)
terrarium plants
frog moss
Zoo Med Hydro Balls (one bag)
an angled box cutter razor blade (worked great to cut/sculpt the great stuff)
A box of disposable gloves (used almost the whole box)
thick ml plastic drop cloth (used a very small amount)
thin landscape fabric (used a very small amount)
2" stiff disposable paint brush (worked great to push around the small rocks and brush off the back ground)
5/8" tubing (about 6")
Most of this stuff I had lying around the house.
First step was to gather all (or most, lol) of the materials.





Next I built the "bones" of the terrarium. I used the egg crate to make a slope for the water to run down and a base for the floor. Its raised up and has a few supports underneath. I used zip ties to hold the pieces to together and also glued them with the Gorilla glue. I left a space for access to the pump also. This took a long time but soon figured out that using small wire cutters made it easy to just cut the egg crate with out it shattering.














Then I caulked the thick ml plastic to the floor of the river leaving about an inch of over hang. Also, I attached the frame for the pump access opening. Then I stuck the tubing through on of the holes in the egg crate being sure to leave extra sticking out to allow for foam to go around it.




Test fit the "bones" with the pump in place. NOTE: the pump access was really small and while the pump fit I almost got my hand stick in the tank a few times . I had to cut the black lip of the tank to be able to get my tiny hand in there to access the pump and get the tubbing on it. The opening is about 2.5" x 2.5".




I then glued the landscape fabric to the floor on either side of the river. (Sorry must have forgotten to take a pic of that step )


Now its ready for the Great Stuff. I applied a lot and it started "melting" so just do a little at a time. At this point I cut a Jiffy pot and placed it up side down to create a cave and applied great stuff around it. Also, I took two more jiffy pots and stuck them to the great stuff where I wanted plants to be in the end. You can also see the landscape fabric in these pics (its grey). I also out lined where the soil will be to help hold it back and to make a river bank.


First coat of great stuff:




Second coat of great stuff and touch-ups. I stuck the fake plant sticks into the great stuff but this was pointless. Toward the end of the process you can poke a hole in the dried foam with a small screw driver to locate the "roots" where you want them. Also, be sure when the screen top is on the tank there is NO room for anything to get into the pump access hole.




Once its dried (see can), you can carve out your river bank shape and I made the opening to the cave bigger.






Some of the foam was still oozing out so I had to let it dry overnight.




I carved out the back of the water fall area to allow more room for rocks.




During down time while things were drying I worked on the roots. I took the fake plant sticks and coved them with a decent layer of caulk then dusted it with the ground coconut bark (forest bedding) and set them aside to dry.




Once I was happy with the design it was time to get messy . Wearing gloves, I applied caulk to the foam and smeared it around with my hand being sure it wasn't too thick or to thin. Then after wiping the access caulk off my gloves I applied the dried forest bedding to the caulk getting it in all the cracks and crevices. You can always go back and touch it up when it dries a bit.




I didn't put forest bedding were the rocks will be, just caulk.








Note: I didn't apply forest bedding to the river bank either, only on the right and left sides where the soil bumped up to the glass.


After the caulk dried I brushed of the access with the paint brush and blew it out of the tank with an air compressor on a low setting.


Next, with the same technique I used for the walls, I applied caulk to the river bottom and banks and sprinkled the large grain sand on to the caulk.




Then I built up the front of the river with larger stones at the bottom reducing the size as I went up gluing them in place with caulk. I put smaller pebbles into the gaps between the larger stones and where there was caulk showing I sprinkled sand on to it to hide it and give it a natural look. Note: make sure to not seal the front of the river completely because water needs to get thought and back to the pump, leave small gaps between stones. This also serves as a type of filtration. I created a little of a slope on each side of the river too so any creature can get out of the water.






For the actual river I made the bank by laying a bead of caulk then sprinkling a mix of pebbles and sand on to it then brushing sand against to it to fill any gaps where caulk may be showing.












Next I placed the rocks for the waterfall. This took a white to get right. Then glued them in place with caulk.




After they dried a bit I laid a bead of caulk around the falls and tube and sprinkled the pebble/sand mixture over it. Be sure to create an edge so the water runs down the face of the falls and not down the back or off the side. It took a few layers of pebbles and a few trials with running water to get the flow right. It took a while because you have to let the stones dry completely before caulking the next layer on.