Burn or bugs?

This is so discouraging. I'm exactly 2 weeks into my second grow of 4 plants, the first grow was literally demolished by ?? 3 weeks into flowering and had almost no yield. I say '??' because we still don't know what it was, the CFL growing forum said thrips or spider mites (https://www.rollitup.org/bugs/473163-what-causing-these-spots.html).

The plants are already showing the same signs as the ones from the last grow despite adding a HotShot to the grow box. Below are pictures of the box, an affected plant and a healthy plant. It looks like burn, but they all receive the exactly same amount of light, nutrients, water and air. They're watered daily at this point and I've added a small amount of Organic Choice blood meal; but that's it for nutes.

Does this look like anything specific to anyone?

They look like shit...get a thermometer man...it looks like a combination of too much nitrogen(from the blood meal) and way too much heat...and stop watering daily...unless that soil is crispy which I doubt it is since you didn't add any extra perlite to it...you are just suffocating the root system by overwatering it.

I have a thermometer, it's consistently 85 degrees, but there is heavy ventilation bringing in cold air. I can see too much direct heat from the CFLs which is also drying out the top of the soil...the reason I water them everyday is due to the soil being crispy on top. But if this is heat + nitrogen related, that's something I can control. I'm worried about seeing bugs again.