New at this growing

hi im new at growing i have 2 young plants (3 to 4 weeks old) and they each have time release soil is that bad for them? the tips of the leaves are brown. what should i do to help them out should i flush them? and if so how do i do that????????

welcome to the forum. Pictures would help a bunch. If this is happening on just a few leaves it may be normal growth for four week old plants, it could be a problem....without a picture it will just be a guess. VV