Sudden switch to only fart/fairy eggs in 2 sex links

[Sailaway806]

I have 4 hens - 2 EE, 1 black sex link and 1 red sex link. All are 2 1/2 years old. Starting this last Saturday, my red sex link - out of the blue - started laying fairy eggs. No regular eggs. We have now had 4 straight days of fairy eggs from the red. One each day in the nesting box PLUS a soft shell fairy egg in the coop each night. The black sex link has laid 3 fairy eggs over the last 4 days - no regular eggs. History: When the girls began to lay again this spring, the black sex link would lay a fairy egg once every 6 - 7 regular eggs. Red sexlink has been completely normal lay until now.
My first thought was age - but seems odd that BOTH would switch to ONLY fairy eggs at the same time and the red sex link with absolutely no warning.
Both of my EEs are laying normal eggs at normal production.

All are eating, drinking and acting completely normal.
Any thoughts????

 

[casportpony]

What are you feeding them?

 

[aart]

How hot is it...any panting and/or wing spreading?

 

[Sailaway806]

How hot is it...any panting and/or wing spreading?

It's Florida - so yep - it is hot. I expect a decrease in egg production with the severe heat, but when the fart eggs started, temps were still where they had been for about 2 months with normal production. Both of them have since laid 1 normal egg and 1 fairy egg each in the last 7 days so at least we have seen 1 normal egg each.

 

[Sailaway806]

What are you feeding them?

They are on Purina Layena (same diet for last 2 years) with treats (yogurt once a week, couple handful mealworms daily and watermelon or grapes once a week). Free choice oyster and crushed egg shell. Free range for about 2 hrs per day. No changes in diet or environment.

 

[HENS-and-MARES]

Are you sure they are eating the grit you’re giving them?

 

[Sailaway806]

Well, I think I have my answer. I talked to a poultry expert in our area and showed her my laying record. She gave me the bad news..... They are 2.5 yrs old and this would be their 3rd laying season. She said in her experience that sex links are done between 2 -3 yrs old and likely are in their final year of life. She did say it was to my benefit that I didn't use lights in the winter and let them rest. She also indicated that a high number of fairy and small soft shells indicates that they are likely going to be prone to internal egg laying/egg peritonitis. Of our 4 girls, one of them is my son's favorite and literally comes in to watch TV with him. Preparing him now

 

[Sailaway806]

Are you sure they are eating the grit you’re giving them?

In Florida - plenty of grit. Soil is super sandy (all size). They are eating plenty of crushed eggshells - probably twice the amount they ate last year.