While doing some research on medications I came across this rather nice diagnostic chart and thought I'd share
.
http://www.aquatronicsonline.com/hobbyist/hobbyist3.htm
I found on it what was most likely the ailment of my Tetras, Myxobacterlosis.
Symptoms
• Lumps on the Fish's Body
• Whirling or Spinning
• Discoloration
• Black Pigment on Fishes
Causes
• Overcrowding
• New Fish
• Overfeeding
• Myxobacterlosis
Fish prone to condition
• Goldfish
• Tetras
Treatments
• Phenocide
• Flukes Control (with Nitrofura-G After 24 hours as a follow-up)
• Hex-A-Mit
• Isolate Infected Fish
Linear Mode
