Thanks for replies.

They are about 5 weeks old. I would say they have 4 sets of true leaves but they are about 5 inches tall.

I am trying with the ph, i use filtered water which is 5.9-6.0, but i did let the cartidge get a bit old. Thats raised it 7.0, the same as our tap water.

No its not a mirror, its mylar.

I tend to water every 3 days, but I have not had the soil completely dry out.