troykd, It sounds as if you have the controller. I suspect that it is low voltage, like 24VAC. You need to add a thermostat to your system. You can either add it before the controller or after. If you add it before the controller, you may be able to use a 120VAC prewired thermostat: http://www.littlegreenhouse.com/accessory/controls.shtml But your controller will have no power whenever it is cool and the thermostat has the system off. This might cause you to lose settings or run down the battery backup. Adding the thermostat after the controller is trickier if you have a low voltage system. One option will be to find a low voltage thermostat. I'm sure they are out there somewhere, but I cannot recall seeing one. Otherwise, you will have to use a relay. The 120VAC thermostat will energize a relay when over a certain temp, and the controller 24VAC signal will be conducted through relay and on to the valves. These relays are widely available at electrical supply stores. Be sure to enclose all of this in a protected box to prevent a mishap. Hope that helps.

I'll offer a hobby GH owner answer. Misting serves a few purposes. For me the most important purpose is cooling. You could also use it to increase humidity if it is controlled by a humidistat. It serves to reduce plant water requirements. Finally, I also plan to attach a normally open valve as an emergency backup so that the misters come on in case of power failure. It is my understanding that foggers do the same thing but they may be more efficient at cooling given the fact that the water particle size is so much finer (smaller). The terms are confusing, though, because I have tried "fogger" nozzles that produce a spray more coarse that the "mister" nozzles that I use already. I don't separate the propagation area from the rest of the GH.

Mist systems don't have to be expensive: $300 bucks makes a 450 square foot mist yard. 1. DIG interval timer & valve. About $100. 2. 6 fence posts. About 20 bucks. 3. 10 stud length 2x4's. About 20 bucks 4. 7 16 foot 2x4's. About 30 bucks. 5. 200 feet of 75 psi rated 1/2" water line. About $40. 6. 240 low pressure misting jets (About $100 -- leevalley.com. I'm sure there is a cheaper source. They are antelco jets, rebagged.) The posts and 2x4's are used to make a simple 16' x 16 foot to 16 x 30 foot trellis. Plant the posts. Screw a 2x4 to the side of the post with a 2' overlap. Screw a second one to the side opposite. Screw the top end to a 16' 2x4. The long 2x4 should be between. Use a single screw until you get the other end up too. At this point you have 3 pi shaped supports in a row, about 15 feet apart. 4 16' 2x4s cross these. These brace the pi trellises from bowing toward each otehr form the tension in the pipe later. Snake the tubing back and forth on the trellis. Cut scrap wood with a notch that the pipe fits tightly in, and screw these to the trellis over the pipe to keep it still. Or pipe hanging tape. Or those copper saddles uses to secure copper water pipe. The pipes should be about 3 feet apart. So if you make a 16 x 30, you will need 6 x 30 feet of pipe, plus manifold pipe and connection to timer. Experiment with a jet to get a handle on the spread, but I think you want them about 18" apart. (Depends on water pressure, and brand of jet.) You want them on both sides of the pipe, so each pipe will have 40 jets -- adjust according to spray pattern. Antelco claims a 0.8 meter diameter, but normally you put sprinklers at a radius apart to compensate for irregular patterns. Punch and screw in the misting jets. Do a single row on two pipes, facing each other. Lay down some newspapers. Turn the system on. Watch the papers and see if they get wet uniformly. You may have to adjust the spacing which means either 60 more feet of pipe or a hatfull of goof plugs. The rationale behind 3 foot spacing: If you use standard 21x10 plant trays, you have a 15" aisle between rows of trays. This leaves no tray right under the pipes, which drip in use, and drain when the system turns off. You might be able to stretch this to 3 trays side by side the long way. Experiment. . Issues: You may need to make a manifold for the pipes so that it starts and stops reasonably fast. Every nozzle will drip. This concentrates too much water on whatever is directly underneath. Easiest way is to run your aisles under the pipe. The ground gets wet. (Surprise!) This can be messy. Cover the ground with old carpet, fuzz side down. Or do the gravel thing. Misting at the edges is erratic, becuase of breezes. This can be used to harden off cuttings that have gotten a start. You can compensate somewhat by scrounging sheer curtains, and hanging them around the mist yard. locate them so they are wetted by the mist. Breezes passing through them will be humidified. Run fence wire curtain height from the ground to hang the curtains. Staple the bottom edge to scrap lumber to keep it from blowing. Note: This will NOT be successful in strong winds. You are building this in a sheltered location, right? You may want to put sunscreen cloth or lath over the top.

You will want good air circulation so Plastic/plexiglass will interfere with this I would use "shade cloth" it will filter the light. permit circulation & still keep the humidity high.....