Aaaand we're back! PACT (due on the 14th) and wedding invitations (for some reason, I have to get them out this week, though I don't understand why I feel that way) conspired to wipe me off the face of the blogosphere, but now that they're basically out of the way I'm free to answer my fan mail.
Okay, so fan mail might be too big of a word, but I did get a request for instructions on making a bottle biome. Hope I'm not too late to be of help!
Step 1: Find 3 clear 2 L soda bottles (the green ones work, too, but not quite) and remove their labels. Cut bottle #1 near the top, after the point where the sides start to curve inward. Cut bottle #2 near the bottom, before the point at which the plastic changes density and becomes really hard to cut. Cut bottle #3 near the top, before the point at which the sides start to curve inward. You'll probably want to start the cuts on all of these with a razor, then continue with scissors.
Step 2: Bottle #1 is going to be your aquatic section, so if you want to take any measurements or mess around with it later you should cut a hole in the side. The easiest way to do this is to stick a small piece of lumber into the bottle and cut out a square of plastic using the razor blade, cutting against the wood so that you don't cut your hand off. Keep the piece of plastic and tape it in place, so that the compartment can remain sealed while you're not taking measurements.
Step 3: Using a decently thick nail (not those tiny ones from Ikea), hammer a hole into the cap of bottle #2 (you should probably take the cap off for this and hammer the nail into that piece of wood you used in step 2). Thread a pre-soaked piece of cotton string through this hole. This will serve as a wick, carrying water from the aquatic chamber into the terrestrial chamber, so you need to have enough string to reach the water below and still make a decent loop above. Using a thumbtack, poke some holes in the part of bottle #2 near the cap, so that water will be able to drain out of the terrestrial section (but not so far up that they will be open to the outside world. Put all the pieces together, fill with some dirt, water the soil, and let it drain prior to putting the whole thing together (if you don't, your water will be really funky).
Step 4: Put all the pieces together. Fill bottle #1 with water (dechlorinate if needed), and then add aquatic plants and fish. Place bottle #2 on top and tape the two together. Plant terrestrial plants and add any bugs or tiny animals you might like. Finally, cap with bottle #3 and tape the whole thing shut, forming a nice tight seal (packing tape is good for this). Place in a sunny spot and enjoy!
Disclaimer: This project involves a razor blade and a hammer. I take no responsibility for your actions or safety. If you cut yourself or smash your wee little fingers, it's your own damn fault.