how to get my hens healthy again?

Hello Michelle.  You are on the right track your DE is good stuff. However this what I do. Red Mite are awful a complete nightmare but you can control them but you do need a little more in conjunction with the DE.

You need to focus totally on the hen house. Purchase Poultry Shield. Flytes O Fancy sold it in the summer for £18 or so.

Clean out your hen house completely. Bin the contents as much as possible. Do not put on the compost. Spray the Poultry Shield in every nook and cranny. You will be horrified how many mite emerge. Zap em with the PS spray. Allow everything to dry out as much as possible.

Make up a slurry of DE an squirt of washing up liquid and some made up PS to the consistency of pouring custard. Hopefully when you cleaned out the house you were able to remove the perches to and clean/spray them. Paint your slurry on the perches working it into the wood and especially at the ends. Allow to dry and put  everything back in the house. Put bedding back (with a good dose of DE)  sparingly as you will need to repeat this process at least twice more to break the egg/ hatch cycle. Leave a space of no more than 6 days between each clean out. It is a great deal of work but truly is worth seeing your hens happy and perky again.

Now for the birds themselves.

Give them in their water a dash of Apple Cider Vinegar, a dose of a good Poultry drink, and about 1/2 a teaspoon full or a little less of garlic granules. These can all be purchased from a decent horsey feed merchant. I use these as a matter of course and I recon to all of them, my hens look wonderful! That sounds boastful. Most look wonderful but many look terrible to as they are moulting but this all helps keep them in good condition to deal with small drops in condition.

You can also add a tablespoon or two of Cod Liver Oil and a couple of teaspoons of Poultry Spice about once a week to their pellets. Wear a marigold glove and mix well. The glove is to stop you hand reeking of CLO Again your feed merchant should be able to provide these.

Make friends with your local independent green grocer and ask for their trimmings. They will probably be delighted to hand it over. String cabbage leaves, apples, pears etc onto a loop of wire and hang it in the garden within reach. I believe it is called 'environment enhancement' in the zoo trade I just call it a fun way to give your hens a bit of extra goodness and extremely funny to watch.

I wouldn't worry too much about the feathers they will grow back and it is possible your hens are moulting, they do at this time of year.

If your cockerel is 'treading' one hen too much you can buy chicken saddles but be aware red mite can hide there during the day...poor hen..so check every day. Alternatively cut his spurs using a hack saw being very careful not to cut the quick. If you do not feel confident doing that use sand paper to smooth/round off the pointyness of the spurs.

If the hens are sleeping out that is a strong indication that the red mite are still in the hen house. The hens know what's waiting for them once the pop hole is closed . Once you have treated the house try to catch your hens at dusk and gently put them on their perches, talking calmly to them all the time.

They will recover. Keep on keeping on at the red mite. You do have the weather cooling now but from early March get the PS and DE out again and spray about once a moth even if you don't see any red mite....they will be waiting...

Good luck and hopefully you will soon see happy productive hens again.

im just new to all this that all sounds great advice!i  will do that too! i just got all the things mentioned so if you have trouble finding them i can let you know the supplier we used (my other half ordered it all thats why i can't say now).
im at the prevention stage not seen any mites yet but have dusted the whole coop with red mite powder.
my chucks are with us 2 weeks today and had sneezes and runny noses, i got huge jars of garlic flakes from "Range" and i  scatter them with the oyster shell and gravel on a morning they love the flakes, also i add herban fluid to their fresh water every morning and they get layers pellets, then treats in the afternoon and scratch befor bed....within a few days they are fine again....mostly got this from advice of these pages and i have to say they are looking well (apart from poor Lucy with her pecked eye!)
hope you get sorted. x

Hey Jae.

You sound a little 'wobbly' I'm sure you're doing fine. Keeping any kind of animal is always a learning process. Hens are fairly forgiving. You sound a if your heart is in the right place. If you can give you hens your time and attention you will have happy healthy hens that give you beautiful eggs and are a pleasure to have as pets or semi pets. 

as well as treating the coops (treat weekly until the infestation has gone) spray the ground with poultryshield as you may rinse some out of the coop. Get some frontline spray from your vets and put a little squirt between the shoulder blades of each bird to help keep the problem at bay.

If you are using straw based litter eradicating RM might need something a bit more potent than Poultry Shield which is primarily a detergent.  An insecticide such as Ficam W is effective but you need to use carefully observing safety rules.
HF