Maximum Area for HPS Grow Lights
by Ray
(Florida)
I have a 9'x 5' garden area and 2- 600 watt HPS grow lights, and I want to cover the whole area. Is this a good idea? If so, what would the proper spacing of the lights be?
Answer: Ray- most garden plants require bright light, similar to sunlight. For most plants, this means 40 watts per square foot or more (up to 80 watts per square foot, but this is extreme). This is a very general guideline....once I had a 4' x 8' garden illuminated by one 1000 watt HPS light on an 18 inch light mover. If you do the math that is only 31.25 watts per square foot, and yet THAT garden grew very well (one of my better ones, in fact).
Because of this experience, I often recommend lighting a 4' x 8' garden with one 1000 watt light on a short light mover, or else two 600 watt stationary lights. Two 600 watt lights give a total of 1200 watts of light....over a 4' x 8' garden area (32 square feet), that comes to 37.5 watts per square foot. This is still a tiny bit short of the 40 watts/sq.ft. that I try to shoot for, but as I mentioned above, I HAVE HAD really good results with less.
Using two 600 watt lights to light a 5' x 9' garden area may be spreading the light just a bit too thin. 1200 watts/45 sq.ft. gives you only 26.67 watts/sq.ft. You may want to consider reducing the size of your garden to 4' x 8', or you may decide to give it a try and see what kind of results you get. The plants in the center of the garden will probably do fine, but the plants at the edges of the garden may struggle and will certainly yield less than the other plants.
When lighting a rectangular garden area with two 600 watt lights simply divide the space in half evenly, then hang one light in the center of each half. It is also important to use reflective material around the sides of the garden to reflect light back into the garden. This allows the plants to actually use every watt of light that your lights are putting out (instead of letting it "leak" out of the garden area unused). Without reflective material, your watts/sq.ft. will be even lower (considerably.
The reflective material is usually hung straight up and down (vertical), and is placed one or two inches away from the plants (to allow a little air circulation). The material needs to go as low as the lowest leaves on your plants, and needs to come up as high as the bottom of your HPS grow lights. Reflective material is often placed around three sides of the garden, leaving the fourth side open for an oscillating fan. The side left open for the oscillating fan should be one of the LONG sides, so the fan can provide air circulation to the greatest number of plants possible.
I hope this helps. If you decide to go with the 5'x 9' garden, I would like to know how things turn out....until then, Happy Growing!
AffordableGarden Design&Setup
Hi everyone, Jason from Jason's Indoor Guide here. When I got started with hydroponic gardening more than 24 years ago, my first garden used rockwool cubes and B.C. Nutrients....and I remember thinking to myself yeah, sure, there may be a lot of advantages to gardening with hydroponics, for example there are very few pest problems, therefore very little pest control, no weeding, no plowing or tilling the soil, no soil testing or having to add things into the garden soil, no watering the garden....but for someone who just wants to grow their own vegetables and have more control over their food supply and the quality of the food that they eat, the cost of constantly having to buy grow media and hydroponic nutrients makes this an expensive hobby for most people...
Epic Nutrient Change
I suppose when you take into consideration how much money you save NOT
having to buy food at the grocery store, it is surely cheaper to grow
your own food hydroponically even with the cost of high quality
nutrients. Nevertheless, I didn't have a whole lot of money to work with
and I needed to make my efforts as affordable and effective as
possible....and in the last 24 years I HAVE learned a thing or two!
As you browse through Jason's Indoor Guide, you will notice all of the
systems that I use personally are homemade systems. As I got 3 or 4
years of experience under my belt, I quickly adopted a preference to
standing water systems and systems that use expanded clay pellets or
lava rock, because the media is re-usable and it eliminates a huge
operating expense. So once a hydroponic system is built, garden
maintenance is minimal- check and adjust the nutrient solution daily,
and to change it completely every 2 weeks....and the biggest operating
cost is the hydroponic nutrients. (and the electric bill, lol)...
Homemade Cloner
And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient teas....like kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.
Unfortunately, I have been gardening for over 24 years and I have only
just recently mastered this difficult skill....and even then, only
because I happened to find a very easy to follow, high quality technique
and decided to follow the instructions to the letter. I produced more
high quality compost in just one week than I was able to use in a whole
year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to
increase the productivity of your food production efforts, while at the
same time decreasing the amount of effort required to grow all of your
own food, and decreasing the total cost of operating your food
production system.
And when I say decrease operating costs, I mean decrease them to almost
ZERO, especially if you are producing your own nutrients...
High Efficiency
Hydroponics
The ultimate solution to eliminate the cost of your hydroponic nutrients: Imagine a hydroponic system that does not require you to buy any nutrients, does not require you to make your own compost, and does not require you to brew your own nutrient tea. Seriously! No cost and no effort as far as providing nutrients to your plants! Plus, at the end of the gardening cycle you harvest all of your garden vegetables, PLUS YOU HARVEST FISH from the system--->
Aquaponics
This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.
Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!
The Same System/ 10 Weeks Later!
