For a 3.5 veg absolutely. Some strains/genetics just don't want to veg that long. You can add nitrogen and potentially ( *not always*) lead to more issues down the road or you can hit 12/12 and ride it out. Either way could work but for this one specifically let nature do its work. The best thing about MJ plants is resilience and the various ways it tells you what it needs. If you add FF tiger bloom it has a small enough ammt of nitrogen to keep it nice and green and has the p+k the plant needs. You don't need to add a ton of things just the minimum. FF should always be half strength. Just my 2 cents.Plants getting yellow tells u to switch to flower??