Yellowing leaves, small buds: Any ideas?

[GrowW33D]

OK, first time growing under LED lights, switching from HID. In veg I had accidentally turned the intensity of the lights up overkill and they started to lose their green color and turn pale yellow. I quickly dimmed the lights back down (70-100watts all of veg) until they started to show they were okay, they recovered and grew vigorously and strong the rest of veg and early flower. I've now noticed early yellowing in flower since about Day 36. The buds seem like they wont grow any bigger, like they are stunted or just stuck the last 21 days. Its now day 57. Is the yellowing because they need more nutes, is it the lights, is it the temp/RH? I was planning on taking these to day 70 because the yield is still pathetic, buds that will turn to popcorn. Im guessing I'm just a noobie with LED and not adjusting the lights correctly for the plants. I almost feel like I have to blow $500+ for a PAR meter. Any help/response would be greatly appreciated

What Strain is it? 4 Blue Dream, 2 Chemdog, 2 Franco Lemon Chese, 2 Super Skunk
How Many Plants? 10
Is it in Vegetative or Flowering Stage? FLOWER
If in Flowering Stage... How Long? Day 57 flower
Indoor or Outdoor? Indoor
Soil or Hydro? ProMix Potting Soil
If Soil... What is in your Mix? Earthworm castings and Perlite
If Soil... What Size Pot? 5gallon buckets
Size (Wattage) of Light? How Many?
Is it Air Cooled? 2 HLG 600 Rspec, currently sitting at 230watts each at about 18-20" above the canopy.
Temperature of Room/Cabinet? 70-82 degrees F
RH of Room/Cabinet? 40-55% Had a dehumidifer running for awhile keeping the RH @40%. Now removed the dehu and its 55-60%
PH of Medium or Reservoir? 5.9-6.2 Using pH drops
Any Pests? NONE KNOWN
How Often are you Watering? Every 2-3 days every plant will get a 1/2 gallon of water each.
Type and Strength of Fertilizers used? Used Botanicare Pro Grow during veg and now using Fox Farm Tiger Bloom using the recommended strength on bottle.
Size or Square Footage of Room? 9×9

 

[Sueet]

Well, I don't use Fox Farms nutes, so I can't help you fix this, but I can tell you the problem is that you are only feeding one part of a 3 part (or more) system.

 

[farside05]

I almost feel like I have to blow $500+ for a PAR meter.

As long as you have the white style LED's (which you do), and not the blurples ones, all you need is a simple $25 lux meter to dial in your lights. See this link. I'm guessing it's probably a nute issue if all you are feeding is Tiger Bloom (2-8-4). Tiger Bloom has very little Nitrogen in it. Even at their recommend 15ml (3tsp) per gallon, it has only 79ppm from Nitrogen. I've found most cannabis likes between 125-150ppm of N to keep them green.