NPK ratio?

General rule for vegitative growth is to find a fertilizer with a 2-1-1 (N-P-K) ratio. That could be 10-5-5 or 15-7.5-7.5 or something similar. I have also seen people veg with a 2-2-1 and even a 1-1-1 ratio with good results. 24-8-16 would probably work, but ideally you want a little more of the "P" value.

Don't feed your plats until the cotelydon (the little round leaves) start to the ferts. This usually happens around 21 days. Start with 1/4 the recommend strength of ferts and work your way up to full strength over the course of a couple feedings.

Good luck.

 

You're using MG All Purpose Plant Food aren't you? Chemical Ferts are not recommended
but they can work OK if you are careful. The dangerous aspect of using chemical fertilizers
comes from the ease of giving your plants nutrient "burn" due to excessive fertilizing.

As mad4reef said, start out with 1/4 the dose the first time, then use 1/2 the dose for
two feedings, and then give it full strength. This helps the plant transition into the nutrient
uptake gradually and since you will be doing this as the plant grows, it's needs will
increase according to what you are delivering. Giving a tiny plant a full dose of nutes is
like giving a guy who never drank before a quart of whiskey -- gotta build up a tolerance!

I've successfully grown using Miracle Grow "Azalea and Rhododendron" Plant Food which
is 30-10-10 for vegging, and the Bloom Boost, 15-30-15 for flowering. Some plants are
more touchy than others when it comes to nutrients as well, but mine were really hearty
and I was feeding them every 2nd watering, with no ill effects. I did once give a plant
double the max dose and it showed nute burn really fast, so be careful.

Hope that helps

~Experimentalist

 

My only comment is that during flowering MJ needs as much K as P - for some reason this fact is not appreciated by all growers.

Small link : http://www.allotment.org.uk/fertilizer/npk-fertilizer.php