Welcome to AFN and the wonderful world of hydro. Sorry you had to take it down. Here's a couple of quick suggestions for next time.
Raise your temp up to around 82 lights on and try to have it drop 10 degrees at night if you can. LED doesn't have the high heat of HPS so you can run slightly higher temps.
Change your light cycle to 20/4 or 18/6. Plants create and store sugars during lights out that the plant utilizes the next day.
Make sure your light is at least 24" above the plants. I run the same lights and any lower and they will bleach the top of the buds.
No need to put the humidifier in the tent, they generate unnecessary heat. 50-60 is fine and what I generally run. 45% is good near the end but not necessary.
If you aren't, monitor your pH and ppm daily. Keep a log. If your plants are feeding properly the pH will rise slightly and the ppm will fall. If it's the reverse, or both are going up, you're nutes are likely too strong.