T5 for seedlings?

[Jorch]

I am thinking of re-organizing the growing area and switching over to T5 lights. The area where the seedlings are has no sunlight at all. They live about 8 inches under 2 42W CFL and are happily growing since I deflasked them a year ago.

My question is, if I move them to a shelf under 2 T5 tubes (the single tube kind with ballasts and plugs), they will be about a feet under the tubes. Will it be enough light for them? Or too much?

If for my other area, in front of a huge south facing window (although keep in mind I am in Vancouver and sunlight is a rare commodity), will a 4 tube T5 fixture be too much for Phrags and Miltoniopsis? The top of those plants will be 5-6 inches under the tubes. Will they be fried??

Thanks in advance!

 

[Ernie]

I doubt you'll burn plants under T5's as long as you have good air movement.

What wattage T5's are you planing?

Sounds like a pretty good start to me. But... The best way to know if you have enough light is... watch your plants and... get a light meter. You can find them for about the price of a nice flask. I'd consider necessary equipment in any collection.

-Ernie

 

[arcticshaun]

I just added a pair of 54 watt T-5's and so far I really like them. I try to start a plant further away from lights (12") and move closer (and towards the centre) until they can be almost touching. I did just burn a leaf that touched the new bulbs. The effective light from any source really drops over distance, so even inches can make a big difference. I don't know much about Phrags (they can handle a fair bit of light?) but Miltoniopsis wouldn't need to be too close before showing a healthy pink tan (mine do OK under two T-12's at less than 6"). And as Ernie said, lots of air movement is a must.

Shaun

 

[aquacorps]

Tha would be way too much light at one foot.

 

[Damas]

My seedlings are under T5 (because I have nothing else) and I noticed signs of over lightning shorthly after I installed them: I had to cover them with a tissue (kleenex), in order to have normal coloration back. T5 are about 50cm from plants, 4x54w. It's ok for adults paphs, but far too much for youngsters.

 

[Rick]

I doubt you'll burn plants under T5's as long as you have good air movement.

What wattage T5's are you planing?

Sounds like a pretty good start to me. But... The best way to know if you have enough light is... watch your plants and... get a light meter. You can find them for about the price of a nice flask. I'd consider necessary equipment in any collection.

-Ernie

I agree with Ernie. Especially about getting a light meter. Also there is a difference in how much lighting different species of seedlings like. Although the multiflorals seedlings generally like much lower light levels than adult plants, they still tend to like more light than barbata sp. seedlings.

Also note there is an inter-connection between light-temperature-humidity. As Ernie mentioned you shouldn't be able to burn seedlings with T5's as long as you have good air movement. This is to keep leaf temperatures down (as opposed to getting too much UV irradiation). Also as temps go up you can loose humidity, and I have found that seedlings are more sensitive to low air humidity conditions than adult plants.

So the trick is to get adequate light levels without cooking and drying out the seedlings. So besides a light meter, a hygrometer and thermometer are critical.

I would recommend:
Light levels of 800 to 1500 fc
Day temps in the mid 70's to low 80's
Humidity at 60 to 80%