[GpsFrontier]

I am not real familiar with artificial lighting so I am going to need to look into the lighting aspect to either eliminate it, or suspect it.

Same Technaflora nutes. Using a 1/2 strength mix of the Veg recipie from their recipie for success with the addition of awesome blossoms for the P and K. PPM hover around mid 700s. I attempted to register on their forums to post that question. Needed an admin to "approve" my registration and that never happened. This was before we left for the holiday vacation and I've not tried again since I've been back.

I found the other thread with there contact information so I will try to remember to call them and talk to someone in their tech support department. This should be enough information to see if they can give me some information. But try to call them yourself if you can.

lights moved down to 12 hour on/12 hour off. Water cycle is still 15 min on/15 min off during light cycle. Once per hour during dark cycle.

This should be enough light to produce peppers, although a couple more hours might be better (but wouldn't cause the flowers to drop off). As long as the roots are looking the water cycle should be fine also.

The ambient temp of the room is kept around 70 (generally 5 to 6 degrees warmer at the surface of the tub lids from the MH light)

Several weeks worth of testing show that the nute temp generally stays within one to two degrees of the room temp though.

I am a little conflicted here. If the room temp rises to 72 and then the lights cause another rise of 6 degrees, that would be about 78 degrees and defiantly to high. On the other hand you said the roots are not becoming discolored. In my case the discoloring was due to extreme high nutrient temps (in the 90's). So I am not positive that you will see it at 78 degrees.

Your system is a combination aeroponic and water culture system, and as you said the lights cause the lids of the system to be warmer than room temp. Because the baskets and the main part of the root system hang above most of the solution, they might actually be adsorbing this heat and be warmer than the nutrients themselves. I am not saying that this is the problem but I would want to cool the nutrients down a bit to eliminate it as a problem. Especially because the flowers dying and falling off is typical of the root system being too warm.

If you need to replace some of the water daily to top it off, you might try dropping in block of ice instead. You could also try filling a Ziploc bag with water and freezing it, then doping one or two in the reservoir every day. I used to take one Ziploc bag and dunk it under water to fill it to keep the air bubbles out, then taking that one and placing it in another Ziploc and dunking and sealing that bag. Then doing it again for a total of 3 bags, to mimimise leaking and diluting the solution. Just remember not to fill them all the way to allow for the water expanding as it freezes. I also have a design for a simple ice driven recirculating cooling system if you are interested.

dedicated AC unit in the room set to 70 degrees so ambient temp in the room stays around there during the day.

I am not sure the variety of your peppers, and if they are cool weather variety's or not. If these are not cool weather variety's 70 degrees would be to low for the air temp. Peppers are generally a warm weather plant and I would want the air temp to be between 85 and 95 degrees.

It's clear....a very slight brownish tint to it from the nutrients, but it's not cloudy at all.

The brown translucent color is normal, as long as it's clear and you can easily see through it. I have found that if the solution becomes cloudy there is something growing in it. Although there may be some nutrients where cloudy is normal, but you should see that as soon as you mix it.

Nutrient is changed once a week and i do a full flush of the tubs once a month.

Once a week should not be a problem, you might even get two weeks out of them. Although there are a lot of variables to that, like how many plants, if the plants are heavy feeders, size of the plants, how many gallons compared to plants and even how strong it is mixed. But changing them every week should not be a problem and on the safe side, especially if experiencing a problem and you want to eliminate it as a problem.

I myself like to take apart the pump and clean it, as well as scrub out the nutrient tank with every nutrient change. But if the solution is clear, the roots have a good color and you don't see much, or anything growing on the inside of the reservoir that should be fine. But you should at least clean the screen for the pump every week regardless (if you don't already) to keep it working properly.