First thread of my own after 4 years and 2 DC and it's about chickens! 
Sorry it's a long one........
So, we were planning on getting some ex batts and had it all thought out. DH is building me a walk in run and coop to sit inside. So far so good.
Except we have aquired 2 silky hen's yesterday ,wooden coop and run all in one jobby. The plan is still to build the new coop/ run and move them in with some other hen's when it is ready.
Now back to the silkies. They are approx 14- 18 months old at a guess by what I have been told. Never been treated for mites / worms as not an issue 
Rarely lay and just look a bit bedraggled.
On inspection, they are crawling with mites and the coop has red mite. Even putting food in has tiny grey mites crawling on me
I have been to the local agricultural store this morning and bought total mite kill spray for the coop and red mite powder for the chickens. I also got some apple cider vinegar and some layer pellets as they were fed some sort of mixed corn before. Diatomaceous earth on order.
I am going to do battle with the coop once the toddler is having his nap and give the chickens a good dust.
Any advice on tackling this quickly? Also anything else I can do to help the chickens gain some condition?
I have read a lot but have no real experience with chickens and would appreciate any tips.
Thank you for reading!