API Melafix vs. Seachem StressGuard: Uses, Labels and Limits

What the manufacturers say

API markets freshwater Melafix for bacterial infections and damaged tissue. Seachem describes StressGuard as a slime-coat protection product with protein-active colloids that bind to exposed wound proteins. These descriptions do not establish that one product cures severe infections better than the other.

Important differences to check

• Filtration: API advises removing activated carbon where possible during Melafix treatment. Seachem says chemical filtration does not significantly affect StressGuard.
• Protein skimmers: Both manufacturers advise turning skimmers off during treatment. Our previous claim that StressGuard could be used with the skimmer running was incorrect.
• Other medications: Seachem excludes copper-based medications from StressGuard compatibility, including Cupramine. Do not assume all combinations are suitable.
• Product variant: API sells separate freshwater, marine and pond formulations. Do not transfer dosing directions between them.

What this comparison cannot tell you

There is no head-to-head trial presented here supporting a universal winner for fin rot, serious wounds or particular fish species. The earlier claims about guaranteed superiority, oxygen demand, universal betta safety and colour changes proving wound binding have been removed because this page did not substantiate them. Worsening wounds need reassessment rather than confidence in an unsupported comparison.

Read the current directions

Use the instructions for your bottle, including its treatment duration, water changes and equipment precautions. The calculator scales stored doses; it does not diagnose disease or choose a treatment.

• API Melafix: product directions and FAQs
• Seachem StressGuard: product directions and FAQs

Sources checked 27 October 2026.