The science

How dissolved organic carbon
impacts fish growth

Why dissolved organic carbon — and the phenols within it — quietly degrade fish health, growth and FCR in recirculating systems.

What is dissolved organic carbon?

Dissolved organic carbon (DOC) is a mix of organic compounds that accumulate in the water as a by-product of digestion. In a recirculating system, where water is replaced slowly, these compounds build up over time rather than being flushed away.

Among them, phenols are particularly damaging. As their concentration rises, they place the fish under constant low-level stress — which shows up as poorer growth, compromised health, and off-flavour in the flesh, long before most farmers connect it to the water itself.

The symptoms it causes

If dissolved organic carbon is building up in your system, it typically shows up as:

  • Poor fish growth
  • Poor overall fish health
  • Eroded fish fins
  • Slime and mucus on the gills
  • Poor water quality
  • Off-flavour in the flesh

The research

The link between dissolved organic carbon, phenols and fish performance has been the subject of extensive independent research, conducted as part of a doctorate. We’re making that work available here so that any biologist or scientist can review the evidence for themselves.

Research & supporting documentation coming soon

We’re preparing the supporting research for publication on this page, so the science behind CarbonClear can be independently verified. Check back shortly, or get in touch if you’d like to discuss it directly.