Questions

• When should my seedlings go under the light?
• What distance should my lamp have from the seeds?
• What is a good temperature for germinating seeds?
• Could my germinated seed have rotted?

When should my seedlings go under the light in my expando garden? Do I wait until there are leaves?

The seedlings require light as soon as they germinate,  otherwise they will s-t-r-e-t-c-h looking for light. The light  should not be too strong at first. If you are using a metal  halide, simply keep them off to the side a bit (not directly  under), keep the light at 3' or so above and diffuse the light  with a piece of thin white plastic.
 You can place them in your expando at the 2nd set of true  leaves.

 

I have a 400W Metal Halide and I’m trying to germinate seeds. What distance should my lamp have from the sprouts?

When germinating under halide keep the bulb at the ceiling.  You can diffuse the light by placing white plastic over the  container, a common white garbage bag will do. The light is  very intense (and you will be thankful later when your plants  are bigger and growing rapidly!) so 4' is the absolute closest  the bulb should be from the containers. The light can be  lowered slowly as the plants grow till they are within a foot of  each other. A 400 watt is good for your size area.

 

What is a good temperature for germinating seeds?

The temperature should be no higher than 74 degrees F.  Too high of a temperature would fry the germinated seedlings.  (in older plants it causes them to stretch, so it is an important  factor throughout the growth cycle)

 A germinated seed should have sprouted in one week.

 

My seeds are in Rockwool, I did water almost daily. Could the germinated seed have rotted?

Any problems in Rockwool can usually be countered quickly.  Because you mentioned the bean seed had rotted, it seems to  me that the seed could not breathe. The Rockwool must have  an air space underneath it. Is it possible that the cube was  sitting on a flat surface? If so, the bean surely would have  rotted. A germinated seed should have sprouted in one week.  The temperature should be no higher than 74 degrees F.