Hi Dale,

I just purchased a 400W setup the other day. I can't speak from practical experience but the guy at the hydropinics shop said that 400W would cover a 4' x 4' area. This concured with most of my previous reading on the topic. I have also come across some articles that suggest 6' x 6' area. I guess it all boils down to how much height between plants and light.

Hope this helps.

Bill

Hi Dale, depending on your growing area, you might consider using a high pressure sodium light. My growing area was about 2 foot by 6 foot. The HPS was a 250W unit bought at a Lowels or Home Depot. It was under $100. The light assembly is made to attach to a wall or pole. I used sheet rock screws to mount the assembly, and adjusted the height of the light as the pepper plants grew. My timer turned on the light and a small fan directed toward the plants. With about 18 hrs of light, the plants grew well. I did have a second growing area using a 1000W MH and the grow area was a small kids swimming pool about 5 foot in dia. Light weight chains were used to adjust the height. As you might expect, growth was good, but temprature control was a problem in the 6X6 room. I sold the 1000W system because the results with the 250W HPS was working well. My present system (under construction) will use three 4 ft. florescent fixtures suspended by chain with a small fan to keep the air moving. Good luck, chuck

It boils down to how much light your plants need. You can cover a football field if you want, it will be bright enough to read a book but not to grow a cactus!

Covering 6'x6' will be enough for houseplants, shade plants, etc. Covering 4'x4' will be bright enough for getting veggies or annuals to potting out stage but probably not enough to grow them to maturity. Adjust the reflector and mounting height to get the light intensity you need.

HPS gives you more light, but some plants will etiolate. Definitely try HPS if you are supplementing good natural light. You could try it as a standalone light but expect to change if you have problems. A 250W HPS will not be equivalent to a 1000W metal halide, maybe as much light as a 300W metal halide.

Heat output is simple to judge because it is printed on the bulb. 1000W is more than 750W is more than 400W is more than 250W. There is no difference between metal halide, fluorescent, or HPS, they all give out the same heat at the same power level.

Hi again Dale,

In addition to my original post, Shrubs N Bulbs and Chuck make excelent points. I should have mentioned that I'm growing hot peppers in a 4x4 area with the light on adjustable chains.

One other item you may want to consider, whether you build or buy a setup, I purchased an auto sensing electronic balast that is good for both MH and HPS. I figured to extra cost would save me from buying two units, one for each type. It will give me the option of MH for growth stage and HPS for flowering / pepper production.

Cheers,

Bill

I have approx. 250 pepper seedlings under 26 4' fluorescents about 10 plants are currently showing blossoms which I am pinching off continuously I am just looking for other options that i can use to cover a larger area because in another month I am going to be overrun with some pretty large plants. I'll try to word it another way how high above the plants can I put a 250w/400w/1000w hps/mh to cover lets say 100 plants. Do these types of lights have to be close to the plants like fluorescents

No, they do not have to be close like fluorescents - they will probably need to be about 18" away so you don't burn the leaves. If you go to Hydrofarm.com, I think they have an article that tells you how far away to put the lights from the foliage.

How big are your plants and pots going to be? Can you estimate a square footage area for 100 plants?

I have a 400W metal halide for tropical hibiscus, which are high light plants like your peppers. I would say the high light area is no more than 4x4 feet. Heat gets to be an issue, but hibiscus and peppers shouldn't mind that.