Running Mortality Syndrome (RMS) in Vannamei on Plastic lined ponds.

Hi everyone, hope your all coping through this long pandemic. I'd like to know if anyone here has had hands on experience with Running Mortality Syndrome (RMS) in Vannamei on Plastic lined ponds.

As you can see the photo shows all the legs are missing, the basket holds this mornings find of 1.5kg roughly 2,000 pieces @1.2 gram 

We have 2 ponds that started on the same day, exactly the same procedures and identical water management has practiced, Pond 1 is DOC 25 @ 2 gram and is fine. Pond 2 is showing small signs of Running Mortality Syndrome - RMS

We are DOC 25 @ 1.2 gram (0.8 less than pond 2)

Pond size: 3600m2

Density: 150 prawns per sqr meter

Salinity: 28

PH: 7.4

Temp: 27.5

Transparency: 35cm

Alkalinity: 122

Every day or on the 2nd day we clean the pond bottom

We have done 2 x 20cm water exchanges as we have done with our other pond