m0useanswered grow question 3 years ago Few things.
Your should link you diary to the question so people know what your setup is and can see photos and other relevant info about the grow.
Your profile has a lot of open questions.
You should close the old ones by selecting an answer.
If you NL is the same one from your diary, then you don't need zinc.
There is enough in the Gaia Green 4-4-4 alone plus the bat guano has some as well.
Your problems are not with Zinc but something else.
Might be PH, I tend not to go below 6.4 when using dry amendments in coir. liquid nutes you hit PH of 5.5-6.2
Good Luck