I am a Habanero Hydro n00b myself but will do my best, but might need more info first.

I see you provided more info in the lighting posting. You have T5 bulbs in a 4x2ft fixture, and another single T5 bulb, right? Do they have reflectors? How far from plants to lights?

The only way to really know how much light your plants are getting would be to use a PAR meter. Where do you live? Can you borrow one possibly from a hydro shop or fish store?

Also, do you use an EC or PPM meter? It's hard for people to know exactly what your new nute mix is like, especially since Tiger Bloom is not a hydroponic nutrient.

And are you testing the pH of your res? If you are just adding limestone without testing the pH, you could possibly be making a bad problem worse instead of better.

Sorry I cant really advise you on why the blossoms are dropping without knowing more, and maybe not even then... especially since I am currently in the middle of my first DWC experiment. I didn't even use seed, I bought seedlings and transplanted. My plants dropped their nicest big flower yesterday which was dissapointing, so I may not be the best person to advise you. From everything I have read, blossom drop is relatively common unless everything is just right. Could be overwatering (maybe lower res a tad? that helped my plants during transplant shock), could be nutes, could be light.

I also have a an 8 bulb T5 light and never got any of my super hot peppers to set fruit. I figure it is just not enough light but without having an HID light to test with I can not say with any certainty.

On a side note, peppers cross pollinate. Two different pepper plants in close proximity like you described will create peppers that are hybrids that combine the two pepper genes. You can make a mild pepper hot this way. You can also change the flavor of both pepper but since it is not controlled you would never know how much of a mix is in each pepper. Just something to think about.

I would put the light right ontop of the plants and leave it on 24/7 for maximum photosynthesis. many will disagree with me but if the plant is not getting intense enough light then the day needs to be longer.

Ambient Temp is another area that you should look at. Peppers like to be warmer than most all other garden plants. Not only above ground but below also. Cold roots and warm leaves send a mixed signal. Keep the water temps around 75f if you can, no more than 80f. I think at 85f there is no O2 available so not too warm. Hobinaros like the temp high like 85f but not more than 95f and higher humidity.

I'll try to keep an eye on the thread and see if I can answer any other questions or clarify what I have said already.

Flower drop probable causes:

1. Day temp too high >95F
2. Night temp too low 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.

This seriously sounds like you need to check your magnesium and calcium levels. With those out of whack, exactly what you describe tends to happen.