Is 8-8-8 Powerful enough?

Hey folks,

For the last 2 waterings, I've added some 8-8-8 fertiliser , but I'm concerned it's not powerful enough for my plant. The leaves at the bottom are turning yellow.

I doubled the dosage and watered last night, but I'm not sure it was the right move to make.

If I double the dosage, does that make 16-16-16 ? Or is that not a good idea? I'm thinking maybe it's not as easy as that.... Maybe I should go out and buy some more powerful nutes.

Picture attached.

too too strong maybe 1/2 power

hows you're ventalation got a fan on the go also is it sterilized soil (multi compost) you've got mixed with the perlite. blood, fish and bone is a good veg fertilizer.

Hi widowman, thanks for chiming in.

I've got a top and bottom fan in my grow box which is baffled to move air up and over the plants. The soil I bought was sterilized with added perlite.

A friend of mine is going to give me the rest of his fertiliser supply which seemed to work well for him.