Mine doesn't even get close to the heater so heating is not the problem
Aura,
Have you tried changing the water more often and get the carbon out? what do you feed it with? does is eat OK?

So I removed the carbon filter out of myfiltration system and have performed a 30% water change once a week and believe it or not - the syno is doing MUCH better! Eats, swims and the white crap is slowly disappearing!

So I ended up adding the Hex-A-Mit treatment at a lower dossage and salt in the concentration of 1 spoon of Kosher salt per 10 gals of water. I know these are low concentrations but I didn't want to stress the scaless syno too much. I also performed a half tank water change and took out the carbon ...

I started treating my tank with Hex-A-Mit. I will let you know how it works. It is used against hole in the head disease

I am not sure I am going to try it out but I have read somewhere that addition of vitamines may help so I will try that. Take a look at the disease called Head and Lateral Line Erosion. I think it may be related to that!

Thanks for your update!
The thing is that I have a featherfin Syno that is somewhat similar to the one in the first photo of this thread. Although, he is not as white as the one in the photo - he has a bit of white there and white dots along the lateral line. As for the prime, I already use it....
I ...

Are there any updates on the whiteness of these beautiful Featherfin Syno's? any working treatment?