it wont provide all the nutrients your plants need (NPK and all the other trace elements), but seaweed and humus is good for the roots and helps keep the plants nice and green..might leave a smell tho... you will still need additional nutes.
Remember:
for vegetative fertilizers you're looking for something higher in N, and for flowering you need a higher P&K
Make sure the ferts are NOT time-release/slow release
and it would help if they are water soluble