killing two birds with one stone

praefect · Post by **praefect** » Mon Apr 30, 2007 6:33 am

One of my friend has a little greenhouse and last week he told me he's going to setup a small CO2 system based on fermenting sugar in a 2L bottle and then throw it away to be replaced when it stops bubbling..

I said "WHAAA?...."

I think you know where I'm going with this...

He tells me this method is often used to produce necessary CO2 for plants so I'm wondering if some of you guys have this kind of relation with plant growers, he gives me space and temperature and I give him CO2. kind of a nice deal really.

I will read some of his stuff to understand what amount of CO2 he needs and at what rate, etc.. and I should be able to come up with a recipe that will serve both of us.

any input appreciated..

Post by **theholymackerel** » Mon Apr 30, 2007 7:31 am

I would worry that the greenhouse would be too warm and cause the yeast stress.

praefect · Post by **praefect** » Mon Apr 30, 2007 8:48 am

it's a valid point, I'll take measurements in the greenhouse to be sure...

bushido · Post by **bushido** » Mon Apr 30, 2007 8:58 pm

Best way of generating CO2 for green house is to burn a fuel. Most of the co2 generators designed for this burn a natural gas or propane. of course, then the problem becomes cooling. CO2 is only beneficial if sufficient amounts can be generated to fill the area, maintain it for a period of time(exhaust fans have to be timed off here), dump it, and repeat every 4hrs. The sugar is not going to generate enough to be beneficial.

praefect · Post by **praefect** » Tue May 01, 2007 2:21 am

it slowly looks like it's not the coolest idea ever... I thought about the exhaust fans, that's a serious problem cause at the rate the sugar is fermenting, the CO2 is gonna leave the place pretty quickly with these fans on...

We'll try it anyway, we'll try to isolate it to one part of the greenhouse to see if it does any good locally...

I'm reading that some people use containers (plastic bags) fill them with CO2 and then dump the content in the greenhouse... maybe that's the solution for the slow production rate of fermentation

goose eye · Post by **goose eye** » Tue May 01, 2007 2:40 am

dry ice

hornedrhodent · Post by **hornedrhodent** » Tue May 01, 2007 2:56 am

praefect wrote:it slowly looks like it's not the coolest idea ever... I thought about the exhaust fans, that's a serious problem cause at the rate the sugar is fermenting, the CO2 is gonna leave the place pretty quickly with these fans on...

We'll try it anyway, we'll try to isolate it to one part of the greenhouse to see if it does any good locally...

I'm reading that some people use containers (plastic bags) fill them with CO2 and then dump the content in the greenhouse... maybe that's the solution for the slow production rate of fermentation

As long as the greehouse is at the temperature the yeast enjoy - you cant lose - just share your product with the greenhouse owner - he/she will be a winner even if the plants dont thrive.

bushido · Post by **bushido** » Tue May 01, 2007 6:35 am

A more expensive way of delivering CO2 to your plants is to buy tanks of CO2, set up a regulator to the tanks, hook the tanks up to 1/4" tubing which has been perforated every foot with 1/32 holes. Hang the tubing over your beds (CO2 is heavy, it will fall). You should have a concentration of 1,500 to 2,000 ppm (.15-.2%). Increase N, P and K by 20% when using CO2, keep your lights about 12" away from the plants. Your plants should grow about 20% faster using co2, so make sure you check your lights every day. Your fans should be timed off for at least 2hrs when you are releasing your gas.