Hi, my babies are around 3 weeks old and I am about to start adding nutrients real soon. But I want to make sure they are mature enough. How many tiers do they need for me to start adding half strength solution? One of them already has about three and going on fourth tier but the other two are in the middle of their third tier. I am using happy frog soil if that means anything also. Another question of mine is when i do start adding nutrients, should i transplant the kids into new and bigger buckets of fresh soil or just keep the same buckets for a few weeks? (the buckets are only about 6 to 7 inches in diameter and 6 to 7 inches deep)