Hi Joe and welcome to GardenWeb!

Well, most folks use the tubular fluorescent bulbs because they can get so many more plants under them. However, if you just have a few seedlings, thereâÂÂs certainly nothing wrong with using the CFL type bulbs. The Philips bulb in your photo should work just fine. 6500k is great for vegetative growth. Depending on what kind of seedlings (and how many) you intend to grow, youâÂÂll probably need several of those bulbs. Also, IâÂÂm sure you realize that the bulb needs to be mounted in a good reflector, to concentrate those 1450 lumens onto your plants and not the walls :-) Reflectors with vent holes, to let the heat out, are best.

Hope this helps,

Art

Thank you very much for your kind reply!
Is it ok, even if they are T2 bulbs?

Well, if theyâÂÂre T2 bulbs, the only difference I can think of would be the heat. I use mostly T8 bulbs, but I do have a few T5âÂÂs. I much prefer the T8âÂÂs because they donâÂÂt get near as hot as the T5 bulbs. IâÂÂve actually had the tips of plant leaves get burned when coming into contact with T5âÂÂs (never happens with T8âÂÂs). I donâÂÂt have any T2âÂÂs but IâÂÂm thinking they might get pretty hot.

Art