Chia herb garden ??

Does any1 have any experience with chia herb garden , the 1 that comes with 4 little pots and 4 sponge like brown dirt like things that fit into the pots.I recently gnabbed a chia herb garden from my gf. i figured i'd make better use of it. So i pre moisten the 3 of the 4 dirt sponge things and ripped a small hole in the center and put in 3 germinated seeds(btw the seeds are from the dirtiest brown dry compressed weed i ever saw) in the sponges.I put the wshaped leaves other 1 looks normal . they grow to about 2 inches tall and start thier second set of leaves and then that it, for almost 3 weeks no more growth at all lol. What could it be ? my guess is the sponge thing is no good for mj. I can imagince the rootsd may have a porblem growing in this sponge dirt. Thats just me saying things tho since i dont know for sure .Anyway a week ago , since i had 1 more chia herb garden sponge and clay pot i decided to plant 2 og kush seeds i have , one the chia thing and 1 in plain dirt that i mixed in some simple perlite. Now a week later the chia sponge 1 is very fuckin small , it barely grew any stem at all maybe 1/8 inch , fan leaves miniscule about the size of a large grain of rice but still healthy looking. plant in dirt has a normal sized stem of an inch with 2 nice size fan leaves out about the size of a cig filter and second set it on its way , very healthy looking. Yet that still does not prove to me the chia things are bad, anyway if anyh1 know about this crap plz let me know whats up, any info is much apreciated , thank you

 

My assumption is that the plant is unable to grow any type of root system ( hence growth is stunted after 1st true leaf set comes out) because the roots cant break through the sponge. im gonna rip of these open and see whats going on.