Definitely in flower. I clean my rez once a week and while I was vegging I never had to add water in between rez changes. I now have to add 3 gals in between changes. But i am using ebb and flow with a 8 gal rez. You might want to get more info on your grow if you want more help.
yes it does .. dont find out the hard way like i did.. i used to water every 3-4 days in veg now its like every 2 days .. id say take your normal watering cycle and cut it in half and check them then.
Just updated myself on your journal devil. Glad to see it didn't die. Hope it finishes okay. But yeah definitely take it from devils lettuce. It takes more water as it goes into flower.