Fish Pen 250mg, 30 Tablets (1017037)
Fish Pen 250mg, 30 Tablets is a broad-spectrum antibiotic with penicillin that effectively treats bacterial infections like: fin and tail rot, pop-eyes, columnaris disease, gill disease, and other diseases common to ornamental fish.
I have three tanks and it seems any time I introduce a new fish to one of them, something happens and one of my existing fish get sick. Whatever the reason behind it, I've used Fish Pen twice and both times it cleared up the problem. The last time, I had three fish sick with tail rot and Fish Pen lets you treat your whole tank at once.