Ich after 5 weeks hypo

[Benhuan]

Hi all,
I have my fish in hypo at 1.008-9 for around 5 weeks now using a ato to keep salinity stable. However today I noticed a small white dot on my blue tang and only my blue tang (I have a purple and kole tang as well on qt and they don’t have any spots). My question is do I assume that the one dot is ich and re do the hypo from day one and why is it after 5 weeks it shows up I checked slaninity every day and recalibrated my refractometer every 3 days. Any help will be appreciated.
Thanks

 

[Big G]

Is the one spot raised a bit and cottony, fibrous, or cauliflower like in texture? If so, it probably is Lymphocystis. Usually harmless virus, much like the human herpes virus.

 

[Benhuan]

Is the one spot raised a bit and cottony, fibrous, or cauliflower like in texture? If so, it probably is Lymphocystis. Usually harmless virus, much like the human herpes virus.

Thanks for the reply. It doesn’t look like that it is really small white dot. However after closer inspection it looks like it’s not raised and like a flat white dot...