I’m not following the logic of a 5 week difference helping as they age out. There can easily be a 5 week difference just in when they start to lay, much more in when they stop laying. If your intentions are to have a steady egg flow, you might do better having at least a year between adding layers.
I’ve never had a mite problem, so can’t help there. I’m just curious whyyou consider citric acid not natural? It’s naturally present in oranges, lemons, limes, and many others.
I’m assuming one is an egg from your chickens. If so, I’d guess yours is on the right, the Central Market one is top/center and the Kirkland on the left This is based on the Kirkland brand being from WA and “vegetarian fed” and the Central Market is from family farms in Texas