San Pedro grow using LED grow lights

[LEDgirl]

Hi everyone! I am doing a San Pedro grow using Hydro Grow LED's 126W LED grow light.

I received a small cutting of the San Pedro in Oct 08 from a friend of mine. At the time, the little cutting was only about 6 in tall. Being a first time cactus noobie, I watered the cactus every 2 weeks under a 150W HPS. Later, I started giving it Oneness from Humbolt nurtients. I noticed after a couple weeks that the cactus wasn't growing and showed signs of burning. I later found out that the nitrogen content in Oneness was too high, therefore burning the roots. I don't have a picture of my cactus when I received it, but here is a picture of the cactus about 1.5 years later (it's been topped/cut twice).



After the second chop, I decided to grow my second generation (see pics below) under a LED grow light. Cactus, like other plants with leaves, go through the process of photosynthesis. Regular plants process photosynthesis through their leaves. Cactus, on the other hand process photosynthesis through their stem due to the lack of water but hot, dry weather of the desert (where most cacti are found). Knowing this information, I knew that by targeting peak absorption wavelengths for photosynthesis, my cactus farm would grow at least twice as fast as they would under the 150W. I am using Hydro Grow's LED grow light because they target all 4 points of photosynthesis (440nm/660nm: Chlorophyll A and 470nm/640nm: Chlorophyll B). Also, the infrared LEDs help to stimulate cell synthesis and well as aid in stress relief.

This is about 6 weeks into using LEDs. All of the cactus in the 2nd gen are all from the original cactus.

[iann]

Which of the Hydro Grow lamps are you using? How big is the growing area?

I don't know what dilution you were using with the fertiliser, but if it burns then just dilute it more. It might have been the HPS scorching the cactus. Oneness is 5-9-4, I think? Dilute at 1-2 teaspoons per gallon should be good.

[Josh]

The plant I see in the pictures grows better when cared for like tomatoes than when cared for like a cactus. It doesn't like dry soil, but it needs well drained moist soil to thrive.

It can grow up to 3 feet+ a year and up to 5 inches thick.

[LEDgirl]

Which of the Hydro Grow lamps are you using? How big is the growing area?

I don't know what dilution you were using with the fertiliser, but if it burns then just dilute it more. It might have been the HPS scorching the cactus. Oneness is 5-9-4, I think? Dilute at 1-2 teaspoons per gallon should be good.

I am using Hydro Grow’s 2nd Gen 126W LED grow light. The 2nd gen has less white and more red for more photosynthetic energy for the plants. My cactus grow space is 1.76 sq.ft (diameter=18”), with the light being approximately 9” above the plants. The recommended grow space for the 126W LED grow light is 30”x18”.

I originally chose Oneness to give to the cactus because of the low nitrogen, high phosphorous formulation. However, no matter how much I diluted the solution (up to 3x the dilution rate as written on the bottle) it burned my cacti and other fruits and veggies that I grow. I could have had a defective bottle, or Oneness is just crap. So I switched over to Iguana Juice Bloom. The formulation for it is 4-3-6, with the nitrogen level being slightly higher than phosphorous, but the cacti LOVE Iguana. This is pretty bizarre to me since in all of my research of cactus, they require less nitrogen than leaf bearing plants. However, from growing the cacti for almost 2 years now, I’ve realized that San Pedros like to be grown more like regular plants (like tomatoes) than a cactus. I feed them Iguana juice every other week, with just water in between weeks. Every time I feed them the Iguana, they go into rapid growth phase for about a week.

Going back to why I grow using a LED grow light instead of sticking to the HPS. My research on cacti told me that they are like regular plants, in that they go through photosynthesis for energy. If this is true, then it would be beneficial for me to use a light that is formulated specifically for photosynthesis by targeting narrow wavelengths of light that plants use for energy. Any plant respiration/photosynthesis chart shows that plants use primarily blue and red light for energy, while not really using green, yellow or orange. ”In the same way fat provides the most efficient calories for humans, red light provides the most efficient food for plants. However, a plant illuminated only with red or orange light will fail to develop sufficient bulk. Leafy growth (vegetative growth) and bulk also require blue light.” (http://www.sunmastergrowlamps.com/Su...andPlants.html) HPS or MH include all the colors from the visible spectrum, which means there’s “garbage” wavelengths of light that plants do not use. “400 watt metal halide bulb emits about 140 watts of light. If PAR is considered to correspond more or less to the visible region, then a 400 watt metal halide lamp provides about 140 watts of PAR” (http://www.sunmastergrowlamps.com/Su...andPlants.html). So why would I use a high powered HID light which most of the light emitted are garbage? Whereas a LED grow light, we get 80% of useable light for plant energy. As for Hydro Grow’s 126W, it includes 12W of infrared and 6W of white so all in all, I get about 108W in red and blue LEDs, which equals roughly 86.4W of pure plant energy. By using 126W of LEDs (as opposed to 150W HPS), it’s a win/win because I use less electricity (environmentally friendly!), no bulbs to change and I get waaay more plant energy. Ever since I put the cacti under LEDs, they’ve started growing a full inch every week.


Update pics: As you can see, I topped two plants because they were getting so tall. The cuttings were 12.5inches and 7.5inches and the total weight of the cuttings were 224.10g.




From the left side to show the quad headed cactus.


The baby that only about .5" tall grew a full 2" in 13 days!

[king_hedes]

looks like there growing pretty decent