**Materials:**
1. Mother-In-Law's Tongue (or one of the following http://eartheasy.com/blog/2009/05/the-top-10-plants-for-removing-indoor-toxins/)
2. Plastic Flower Pot.
3. Porous plant Growth Medium (We used rocks made of recycled glass)
4. Epoxy or Saran wrap 
5.1 VWR FLOW METER ACR 2IN.1-1LPM ($74.62 + shipping).
6. 1 Tetra 77855 Whisper Air Pump (Small)
7. 2 small segments of ordinary aquarium airline pump (very inexpensive).
8. 2 1/8-27 MPT to airline conversion valves ($4 for two).
7. Aqua Mist Airstone (5 cm x 14cm)

The first step is to reverse the diaphragm in the pump to convert it to a vacuum. Open up the four Philips head screws on the belly of the pump. Lift up, rotate 180 degrees, and then replace the diaphragm as indicated in the below GIF. 

Attach a small segment of airline tubing from the pump to the top of the flow meter (which you have equipped with the conversion valves at both openings) and then attach another small section of tubing to the bottom of the flow meter. You will have three points where you can adjust the flow rate (the meter, and both conversion valves). Open all valves to their most open--while still sealed--position. Once you've started the pump, use the large valve on the flow meter to regulate the flow rate down to .3 liters per minute (or 300 ml per minute).

Separate a section of the plant chosen to use (We used Mother-in-law's tongue). Set aside and prepare the flower pot.

Start By sealing all but one hole in the bottom of the flower pot. (This open hole will be used to insert the aquarium tube) 

Insert one section of the tubing in the hole (roughly 5"), and seal the hole around the tube with the epoxy. 

Fill the pot with 3 inches of growth medium ensuring that the tube is above the rocks.

Attach the airstone intake to the tube inside the pot and cover with more rocks

Gently separate (we're using mother-in-law's tongue) plants, remove dirt from plants
We then filled the pot with recycled glass 3" up from the top, placed our filter in it, then filled another inch of rocks, placed the plant, and then filled the pot with rocks. 

test air flow w/ flow meter each configuration before placing in the pot- 0.65 liters per minute (discard-a-stone coarse bubble), 0.7 liters per minute (aqua mist 1 cm), 0.65 liters per minute (aqua mist 5 cm x 14 cm)

Tube length has a negligible effect on air flow- we tested both short (4") and long (6') and saw little difference between the two. 
Is there a limit for how much air flow is too much for the plant? (temperature difference, etc.)

epoxy to fill in the holes of the plastic pot that we're using (BE SURE TO THOROUGHLY SEAL HOLES), ***seran wrap should work as well***; use one of the existing holes to run the tube through the pot. It's useful to find a pot that has sufficient gaps to run the tubing underneath without crimping. Leave enough room with the tube to have at least a few inches running outside of the pot, Make sure to have enough tubing to allow the filter used to sit above the water level. 

Leave an inch in between the root systems and the air intake system to avoid suffocating the filter without losing air flow within the plant system.
With this setup, we're getting 0.95 liters per minute of airflow.

to reverse the motor
remove diaphragm from the pump and reverse it- vacuum bingo! (GIF LOCATION)

http://www.wolvertonenvironmental.com/airFAQ.htm

More information on plant types usable for the kit:
http://eartheasy.com/blog/2009/05/the-top-10-plants-for-removing-indoor-toxins/
http://www.healthcentral.com/cold-flu/cf/slideshows/10-houseplants-detox-your-home#slide=11