Well I had to euthanise it as it just wasn't getting any better. The kids and wife got upset too so we agreed it was the best thing
I am going to make sure all my polys now have pellet foods as a staple with only the occasional frozen stuff. I won't feed them Prawn again and will use tilapia fillets instead
Thanks again for the help
Point taken but he was really bad-stayed vertical head up with tail on the bottom the whole time barely breathing. There was no way he was going to eat again or through and it was only a matter of time. Not an easy thing to do but I think it was best given the circumstances. I couldn't reverse the deficiency as he would not eat again