@BeefWellingtons, I grow in hempy buckets. The largest pot I'll ever use is 2.5 gals (unless I want a tree but I don't have the patience for a 24 week veg)
You don't need to feed any nutes until the second set of leaves (true leaves) come out. The seed provides enough nutrients until then. After that is when you can proceed with a very light feed, try 1/3 or 1/4 the recommended use. When plants are that young it's easy to burn or damage them.