some seeds better than others?

Hey everyone. I have a very basic question that will help me move on to the next step. My girlfriend and I have begun to grow some plants in soil under a 430Watt Son Agro lamp.

We started 2 plants about 5 weeks ago and they are each about 12 inches tall with a few leaves. The growth has been incredibly slow and I feel there have been much more successful grows I'm sure.

We have failed miserably in other grow attempts, so this is the furthest we've gotten so far.

Just the other day, I found some old seeds that I had packed away in a film canister. I imagine the seeds are around 2 years old. Anyway I put them all in a damp paper towel in a bag and in the dark. After 8 days when I got around to it I looked and saw 3 seeds had sprouted. I planted all 3 seeds but this is what's happened since.

1 of them is growing so fast that the leaf span is probably around 6 inches, while only about 1 or 2 inches from the top of the topsoil. It has been growing for about 5 days now. The other ones who peeked out of the soil took longer to come out, and seem to not really be growing. They each have their two small little pedals and don't seem to be more than 1/2 inch to 1 inch from the soil. Basically there is a gigantic difference between the plant that is growing rapidly and the two that aren't.

To me knowledge, everything is the same. The amount of light, amount of watering, age of the seeds, soil being used. Is it likely that the one doing good is either a more fresh seed or a better strain altogether? :jointsmile:

Could be strain dependent; I got a BlueJay cross from a Toronto local that the seeds were just ridiculously large and burly and the seedlings grew very big very fast in the same tray as an 'elite' strain that was smaller seeds and grew very delicately. Plus some strains are simply better suited to artificial lighting.
FYI seeds are considered 'good' for 5 years and then the grem rate starts to decrease.