The ones I used are commercial grade reactors. The leds do get a bit warm. But, never experienced any ideas issues with cracking. I would recommend running them for 12 hrs. There are remote controlled / manually dimmable or just standard which can be plugged into a timer. I made the mistake of buying one set from walmart and had an issue with one strip. But, it maybe the transformer.
https://www.amazon.com/Lahoku-16-4ft-300LEDs-Waterproof-Spectrum/dp/B0745BXD6L/ref=sr_1_36?ie=UTF8&qid=1515529919&sr=8-36&keywords=Waterproof+led+strips+red+%2F+blue