red bump on aro's tail

[Strad]

there is this red bump/lump on my green aro tail,

add salt and turn heater to 30 deg, add medicure for about 5 days ...

done water changes also about 1/4 twice every week

but there seems no improvement at all,

or do i need to cut away the tail affected?

[vti_eg9]

My red previous have the pimple on the tail ,no matters what i try pimple still there ,no choice bring to qh to cut away the pimple parts