You could try chicken poo tea! It is where you put the poop into a large water container and leave it 'brew' and then dilute it further before using as a liquid fertiliser.
We sometimes get soft shelled eggs (known in our house as mutants) but I can usually track this to some shock or change in environment. Here in the UK we are experiencing a rubbish spring with sudden frosts at tht is playing havoc with the girls!
I took in 2 chickens (one brown and one silver) about 8 weeks ago however our existing 3 girls have just not taken to the silver girl and she has separated herself from them and sits on the house unless they are out in the garden. We obviously had the usual fights to sort the pecking order and...
It was a whole family effort to get the run done but it is very secure. It's when they are free ranging that the issues occur - one attack happened when I was only 10 foot away!