Been using kent/blue seal. My birds seem to like it, and yeah, I pay more, but the birds seem healthier, on it.
I ended up adding a heat lamp to Strutters coop. His comb is messed up now, but not from frost bite. It's white, scaley, crusty. I think not only with the feet problems, which I am treating as if it were gout, and with molting... I am thinking that poor bugger may have dry pox. Gracious. He looks all jacked up, that's for sure.
Reason I dont' think it's frost bite... Well, Texas has this HUGE comb that flops over a bit (Which makes me think she's not a marans, but possible an orp/marans mix or an orp all together, she is the fatest butt chicken in the yard, stand completely different than marans standards, but she's lovely and I don't care one wit if she's not marans) and her comb is just fine. She has a HUGE comb.
The phoenix handled the cold fine. I did have a heat lamp in there for them though, because I was nervous. Their heat lamp was directly over their water. I did put it in the coop itself on the night when the temps dropped to negative digits, and we had the terrible winds. I don't regret that action either. I didn't want to move Gains to the garage with Mr. Ed and Red Devil. Those two boys get along, even with the other two roosters in there. Gains though, he's a terror on his rivals tails. And he's loud. Did I mention he is loud?
Well.. Off to cook some trout. Yum.