thats normal, you will see any different number of leaves. 4 is abnormal but its nuthin to worry about. those 3's will grow into 5s then 7s then 9s and so on. and ive never heard of liquid seaweed so i cant help ya there. u really want to stay with just water as long as u can because as i said u dont want them to become dependant on chems like mine did. i wish i had never messed with chems in the first place as im sure they would be alot healthier if i had of stayed natural. one question for yah, how much bigger is the pot that u transplanted them into compared to the old one? its best to transplant into a pot no more then 1.5x the diameter and depth of the previous, because as i said transplanting into fresh soil is good for them, but u dont wanna go from a small pot to a huge one.