indoor Indoor Jalapeno - Bud Drop

Planted a jalapeno miracle growables (ready to plant jiffy cup) back in Feb. or March, can't remember.
 
Pot: 5 gal bucket drilled tons of small holes in the bottom
Soil: miracle grow potting soil
Lights: 16hr on 8hrs off since planting. Started with two T8 bulbs, just yesterday switched to 4 T5's.
Temp: low-70F, high-73F
Humidity: 30-40%
Fan: the last 10 days or so, during the 16hr light cycle a fan lightly circulates air
 
Everything seems fine, but Im noticing quite a few buds are dropping, almost all of them. I lightly shake the plant each day, sometimes lightly touching the blooms to ensure pollination. It just seems like after 3-5 days the entire bud, bloom + stem fall off.
 
I took some close up pictures, it looks like the stem right where it attaches to the plan just gets yellow-brown-thin, then falls off?
 
I read all about no-no to MG soil, so I'm starting over with Fox Farm Ocean potting mix and new Hab, Jal, Dwarf Tomatoes, but that's another post.
 
 

 

 

 

 

Flower drop probable causes:
 
1. Day temp too high >95F
2. Night temp too low <65F or too high >85F
3. Too much nitrogen fertilizer
4. Too much water
5. Low light levels (reduces fertility).
6. Very low humidity (reduces fertility)
7. Poor air circulation (air circulation contributes to pollination).
8. Lack of pollinating insects.
9. Size of pot
10. Too much mineral in feedwater.
11. Too much grower attention/anxiety.

I'd be leaning towards low humidity. Couldn't get pollen indoors until I went over 50%.

miguelovic said:

I'd be leaning towards low humidity. Couldn't get pollen indoors until I went over 50%.

Click to expand...

I'll put a tray of water inside the grow box and see if it raises humidity.
There's a dehumidifier about 10-15 ft away from the grow box, outside of the room; I'll keep door shut.

There may be a few reasons... the 2 T8's maybe weren't enough either. But I have a jalapeno under 4 T5's like yours are now and it holds pods just fine. In fact, I don't think I've seen a bud drop yet. But I have had problems in the past, where I had them under smaller lights and once I brought them outside, they held buds no prob.