Question of the Week:
Hi Nico, We are beginner growers in the northeast, which mean we grow indoors. We have a small closet grow with two 400-watt HPS and eight plants in soilless mix. We are thinking about adding CO2 and wanted to know your thoughts on this for our set-up as well as any other tips you may have. Many thanks for all your work and dedication!

Ari & Jillian, Massachusetts

Answer from Nico:
Hey guys – Thanks for reading and writing in!

It sounds like your off to a great start. I very much like your choice of medium and your lamps are a good fit for your parameters. Here are my thoughts on CO2:

Using CO2 in an indoor garden is really taking it to the next level. The trick comes from good growroom planning at the onset of your project. If your ventilation and circulation systems are set up properly, it should be no problem introducing usable CO2 supplies into any type of indoor grow.
Today’s market offers cheap, simple and organic CO2 systems such as the CO2 Boost, which utilizes a composted substrate to naturally create the gas and an air-pump to distribute it to the garden. This is an easy and affordable solution to taking your CO2 levels past ambient atmospheric levels of 300-400 PPM, and can get  a small room up to 600 PPM. Other CO2 solutions include a tank and valve regulator system or in-room propane burners (not recommended for a closet). Tanks are generally easy to use and accessible in any town (just make sure they are chained to the wall or floor… just in case).
There are two things to remember when using CO2; first, only use CO2 during the lights-on periods in your garden and second, make sure your exhaust systems are coordinated with your CO2 releases so that your gas doesn’t go to waste.  

Mylar is a great addition to any size growroom as it greatly increases the amount of light available to your marijuana plants. Many growers who are just starting out and building a room on the cheap will opt for aluminum foil or other reflective materials (i.e., white paint) to cover the walls of their growroom. Mylar is a product of DuPont, but many other trusted manufacturers sell it as “reflective” or “metallized” polyester.
When choosing your reflective material, check for faulty products by testing it for transparency. Any light coming through the sheet is bad news. Also, choose a material that is thicker rather than thinner. Two millimeters is more durable and easier to work with. Obviously, the higher the reflectivity rating, the better it will be for your garden.

Thanks for reading everyone and remember: Grow… And help the world grow, too!

Got questions? Email ‘em over to Nico at and be sure to put “Nico’s Nuggets” in the subject line!