Building a homemade propagation dome to start my seeds in from a large rubbermaid container since I wish to use 4'' rockwool cubes and standard propagation domes are not large enough. My question is how much light from LED's should i use for my dome? I am looking at 12, 24 and 36W led's. Also looking at maybe getting 2 for better coverage for my 5 seedlings. Whatcha all think?