Light for starting seeds

Okay all I have checked the forum and I can't seem to find an answer. If someone has asked and answered the question could point me to the post that would be great.

Here is the question, I am going to start my seeds soon. I am trying to decide if I should just use my ROI 680 to start them solo cups like I have watched about 100 times. Or should I get a propagation dome with a T5 florescent light? Fist concern is will the ROI light be too much for the new kids on the block. Second concern is power consumption. I am not afraid of the bill either way. But as a conservationist I think about my carbon footprint. Any comments will always be welcome. Thanks in advance

4 comments

Comments (4)

Mr. Grow It

Oct 17, 2020

Do you have a link to the T5 fixture you were looking to get? Keep in mind that T5 fixtures are good for seedlings but very inefficient.

The ROI-E680 ran at 40% (lowest setting on the light) pulls about 263 watts. If you're going to use the ROI-E680 for seedlings, I recommend 24" away dimmed down to 40%. That's about 380 PPFD dead-center and 319 PPFD below corner diode. How do I know that? I did a PAR test on that light and created a few videos on it. I'll list the videos below. I also ran this light for several grows.

If you're really trying to calculate things here, you'd have to figure out the wattage draw for the T5. Then you could figure out what the energy consumption $ would be per month for each fixture. Then add in the cost of the fixture and dome.

Here are the videos I mentioned + more info: at 10:12 I talk about what I ran my lights at

Jeffrey Glick

Oct 17, 2020

Replying to

I watched that three for four times and I wrote down all the par numbers as well. Here is the dome I was thinking about Super Sprouter HGC726402 Premium Propagation Kit with Heat Mat, 10" x 20" Tray, 7" Dome & T5 Light, 5 Piece, Black/Clear. according to question and answer on amazon its a 24W light. Now I do not know how accurate they are. All right since this is my first attempt to grow I think I I am going to go with your recommendation and just use the Roi for the entire grow I'm still not sure on the solo cup so maybe just a propagation tray and a heat mat will do. I think you are very pro and if I can emulate you even 1/4 of the way it will all be good. Thanks for the response I appreciate it

Mr. Grow It

Oct 17, 2020

Replying to

@Jeffrey Glick That's a neat propagation kit; I wonder what the PAR output is on that light. $80 for that pretty much doesn't make it worth it huh? You certainly wouldn't use $80 worth of energy in the seedling stage with the ROI-E680.

Solo cups work just fine for the first 2-3 weeks of the plants life. Then transplant into a larger container of course. Sometimes you can get away without a heat mat but using one can help ensure your medium is in the optimal temperate range.

Jeffrey Glick

Oct 17, 2020

Replying to

@Mr. Grow It heat mat added to my garden supplies lol