i used to use those long ago..matter of fact i have a package of those from several years ago..i dont use them any more..they do werk pretty good tho...now i just use the Moist Paper Towel Method to get seeds to pop and then i put them into the rapid rooter seed plugs till isee roots poppinh out the sides and then into solo cups with soil..  after 2 er 3 weeks er so i move them into their final container...GL