grow lights

[Siggor]

would love to get some led lights would this be enough for germinating cacti seeds, give me your ideas please.

cheers guys

[cactophyle]

would love to get some led lights would this be enough for germinating cacti seeds, give me your ideas please.

cheers guys

Just a regular, under the cabinet flourescent lighting fixture should do, but the size depends on how large of an area you need to light. The bulbs should be a full spectrum type for best results, and it should be placed fairly close to the trays, perhaps just inches above the lid. Get a timer too, and I think you're set!

[trucha]

Fluorescents work great but need to be placed close as mentioned. 6-8 inches is a great starting point with some species wanting them closer and some wanting them a bit farther. Watch the color of seedlings to know. Pale or washed out colors means they are too far and reddish or bronze means they are too close. Being sure they are intended for agricultural or other full spectrum applications is crucial as was also mentioned. I'd suggest trying a hydroponic store for the best selection.

LED light panels will be the way to go though once the price drops to a more reasonable level and better thought out designs become available.

Right now performance of LED grow panels is about the same as fluorescents for seedlings with a much higher cost of entry (5-20X depending on the source of either one) (and much longer life of course - 11 plus years is typical but the new generation bulbs promise an even longer life)

One NICE thing about LEDs is the exact spectrum you want can be created meaning you not just use less electricity but waste less of what you do use. The growlight side of the LED industry is still somewhere in between its infancy and toddler years with a lot of nearly worthless stuff being put out by people who are not plant growers and commonly either misrepresent or don't understand the realities of their products. There are some nice exceptions. Give it a just a few more years and the story should be way different.

Currently LED growlights have the same limitations though of needing to be close to the plants for good results.

Edited March 25, 2009 by trucha

[cactophyle]

Here's an idea I'm trying this year for my Turbinicarpus seeds (wish me luck mates!):

I've placed two 16" full spectrum (one slightly more red, one slightly more blue) flouros in a 24" square box basically. On the inside all sides of the box, including the top, are covered with mirrors so the light doesn't get wasted. Hopefully the mirrors will recycle enough light to prevent etiolation or cacti from growing awkwardly towards the light. I have an indoor/outdoor thermometer attached and it shows that inside the box with both florous running the temperature is only slightly higher (5F), which is about perfect because I don't need a heating pad!

I'll be trying two 64 plug Parkseed biodomes inside this box. I heard that those work as great for cacti as any plant. We shall see! I am concerned that the fertilizer that comes with the biodomes is too high in Nitrogen, though that might not be a bad thing for seedlings maybe. Unless advised otherwise I will probably try and use cactus fertilizer instead. I don't think the Parkseed plugs contain any nutrients like a soil substrate would -- it's sort of a hydroponics situation, where the plugs are some type of inert foam-like material, so nutrients must come in the form of fertilizer.

If fresh air becomes a problem (i.e. if mold or algae appear) I will add a fish tank air pump into the box, not directly into the biodomes of course. My main concern is algae, and mold taking over everything, so the insides of the biodomes will get a good hand washing in the sink with lots of dishwashing detergent, and then a rubdown with some ISO alcohol before going into production. Since the Parkseed plugs are the substrate and they are presterilized, I don't really need to worry about sterilizing any soil. I have considered putting a thin layer of course sand on top the seeds, but I'm not sure that will be helpful or neceesary -- I might try both ways to see which is best.

My current plan is to wait 6 weeks after germination before opening the air vents slightly, and perhaps 6 months before the air vents are open all the way. After that the plan is to simply keep them alive, even if that means a whole year in the biodomes.

[Xenodimensional]

I have a usb powered greenhouse that I'm going to flick a few cactus seeds into just to see what happens. It has red and blue LED lights. Will report back if anything interesting occurs. :-)

[Teotzlcoatl]

I just use a heat mat and a single "natural sunlight" blub from the hardware store.

[ddd]

Look into a 250w or 400w Ceramic Metal Halide. I'd say it's the very best you could get. I've seen the 400 in action and it's white just like the sun:) I've read it's bluer than a MH and redder than a sodium. The 250s and 400s run in HPS ballasts.

http://advancedtechlighting.com/cdmed18.htm

[Jack]

HID lights are way too powerful for seedlings, stick with fluro's.

[Gunter]

People have grown the seedlings out under rather bright conditions outside. The sun is more intense than most HID lights.

I have used HID lights on cactus seedlings and found them to work very well, much better for my taste than fluorescent lights. I got better, faster and healthier results with HID than with any other type of artificial lighting including several type of fluorescent lights. When I finally saw seedlings that were nicer than the ones i had grown i was a surprised and asked the person what he had used, his answer? Sunlight, he grew them out hard. Pretty sure he goes by the name of Osprey around here.

[Jack]

I suppose it depends on your circumstances with my limited space and the heat produced by HID lights its not really an option.

[cactophyle]

IMO the heat produced by flourescent lighting is just right. They are required to be only inches from the plants so the ballasts will raise the temperature by a few degress, but nothing major. This practically eliminates the need for a heating pad and kills two birds with one stone. I've always been a fan of simplicity and saving money.

Another cool thing is that small globular cacti, like Turbinicarpi, grow fine under close full-spectrum flourscent light, so it can work beyond seedlings. Do not try this with large columnar cacti (i.e. Trichocereus) though because it is not nearly enough light for them and they will etiolate.

Edited March 31, 2009 by cactophyle

[Gunter]

It is absolutely true in my experience that heat is more of a seedling killer than light intensity.

HID lights can be hard to manage in terms of heat, sunlight too.

I had good results with fluorescent lights before I moved onto HID.

[Jack]

another option for those with limited space were heat may be an issue who want more light is to use somthing like this:

http://www.aussieponics.com/index.php?act=...ae29bace7d1586c

These produce a lot more light than standard fluro, and a fraction of the heat of HID light, friends of mine have had great success with these, they screw into your HID reflector but connect with an adapter the mains power (no need of ballast)

[tobydoo]

I just use a heat mat and a single "natural sunlight" blub from the hardware store.

YES teotz. Remember people cactus are tough bastards by nature. Don't over analyze or baby them. Only the toughest survive....and those are the one's that you want.