For best results, you want to keep temperatures at 70-80 degrees F during the day and 55-60 degrees F at night. So the garage is way too hot for seedlings and adult plants alike. Also, did you cover your seedlings up with a dome? Seedlings don't have roots so they tend to dry out quickly. Domes keep humidity high which keeps them from drying out.

Thank you, Marie! "Crisp" or "clean" are just fine for words...my 86-year-old grandmother, when she last saw a plant photo I'd taken, said, "Oh! That's a nice picture. It looks like it's been sterilized or something." That's her phrase for "clean," basically. At Thanksgiving dinner last year, when I walked in the door, she smiled and told me that I looked "very sterile today." It's a big compliment. :) Hahaha.

Old topic but wanted to share my input. I'm growing hydroponic tomatoes (various strains) at university in a lab setting (indoors under HID lights) and outdoors in a greenhouse. In one of my greenhouse NFT systems, i recently had a similar problem on 1 tomato plant (total 9 plants that share the same res and tubes). But im gonna try to diagnose your issue by mentioning what others missed out on. 1 major cause of leaf curl is compaction of root system (i.e. roots are compressed or dont have enough space to expand). This risk is exacerbated in hydroponic systems that use tubes. This was the problem i had and had to replace tubes with square tubings that have a liftable top. Once you have access to roots, you must seperate them strand by strand (i.e. so they arent sticking together). In your setup, this risk will further be exacerbated because you filled the entire pvc tube with hydroton (right?). Remove hydroton from tube and place the plant in a net cup with hydroton. Nitrogen burns usually cause browning/yellowing of leaves (similar to sun/heat burn) and not purpling. Test your solution for each chemical if possible, or use a commonly employed aggregated measuring device that shows total concentration in ppm (dont let it exceed 2500). In my system, only one plant was affected. Coincidentally, it was the largest of all plants with the most root mass. I let another normal one grow to its size to see whether it would undergo the same problem, and it did. Viral and bacterial infections that cause leaf roll usually cause it to roll up. Same with the physiological roll. If your leafs roll down AND if your stems bend, this is caused by a diminishing turgor pressure (read: not enough water reaching afflicted area). Mist several times when lights are off (no photosysnthesis) and observe increasing turgor pressure (unbending). Or, untangle roots and remove hydroton from from pipes. I tested various growing methods including fully and partially submerged roots. They all work but a submerged root cannot intake oxygen; it has to borrow oxygen from another part of the plant (i.e. a root part that isnt submerged or above ground stem). This requires energy for transportion and isnt the most efficient (optimal) way for growth and cellular processes. Lastly, an airstone in the reservoir is useless unless the reservoir is completely airtight all the way up to the plant holes. Better to keep small airstones in the pipes right under the plant roots. Those that say aerating the res prevents bacterial development.. is false. If you dont have air in res, you will get anaerobic bacteria (they grow/accumulate slowly but acidify the solution); if you have air in res, you get aerobic bacteria (not acidifying but grow extremely fast). Most bacteria prefer aerobic environments for optimum growth.

I would agree with the second person ...almost all jm's like afternoon shade and 5-6 hours of morn. sun except some varigated varieties that burn really easily.... BUT that being said i think it's common sense NOT to move it in it's current stressed state ..If it's a gal you could easily build something to shelter it from the west sun or most sun if you feel more comfortable doing so...wait a few weeks and see what happens ..I personally wouldn't move it til fall and dormancy since it is not a happy camper if it makes it that long...two wipe outs in a short period of time...not good IMHO Jm's can take alot and come back from adversity but a double whamo of excessive cold and heat on a cultivar that is NOT hardy and small in size with limited root system..I am NOT encouraged ...BUT good luck David