Best Fish for Biofloc: Species Selection Guide

The best fish for biofloc are the ones that tolerate crowding, handle fluctuating dissolved oxygen, and can actually eat the floc itself as a supplemental protein source — not every species farmers want to stock fits that profile. Here’s how the main options compare.

Biofloc tilapia: the default starting species

Biofloc tilapia is the most common pairing worldwide, and for good reason. Tilapia are omnivorous, tolerate high stocking density, and actively graze on floc particles, which cuts feed cost measurably compared to a pond system. They also handle the swings in dissolved oxygen and ammonia that come with a young or unstable biofloc system better than most species — which makes tilapia the forgiving choice for a first biofloc cycle. See our tilapia farming equipment page for the aeration and filtration setup that pairs with tilapia at commercial density.

Biofloc catfish: high density, careful oxygen management

Biofloc catfish works well because catfish already tolerate crowded, lower-oxygen conditions in pond culture, and biofloc’s high-density stocking suits that tolerance. Catfish don’t graze floc as efficiently as tilapia, so feed cost savings are smaller, but growth rates in a well-run biofloc catfish tank are strong. The main risk is oxygen — catfish stocked at biofloc density with an undersized blower will show stress and slowed feeding before you see it in the water itself, so size aeration for the fish load, not just the tank volume.

Biofloc shrimp farming and prawn farming

Biofloc shrimp farming is where the technology got its commercial start, and it remains one of the strongest fits — shrimp are efficient floc grazers and biofloc’s water reuse suits shrimp’s sensitivity to disease introduced through fresh water exchange. Biofloc prawn farming (freshwater prawn, Macrobrachium) follows similar logic but needs more swimming space per animal and benefits from added structure in the tank, since prawns are territorial and cannibalize more readily under crowding than shrimp do. Browse shrimp farming equipment for the filtration and aeration gear sized to shrimp biofloc density.

Catla fish farming in biofloc and other carp

Catla fish farming in biofloc is less common than tilapia or catfish because catla is a surface feeder that doesn’t graze floc as actively, and it grows larger and needs more swimming room than the typical biofloc tank provides economically. Farmers who do run catla in biofloc usually stock it at lower density than tilapia and treat floc as a minor feed supplement rather than a primary driver of FCR. Other Indian major carp face the same space constraint — biofloc tanks favor species that stay productive at high density, and carp generally need more room to perform.

Murrel fish in biofloc and snakehead fish farming in biofloc

Murrel fish in biofloc — and snakehead fish farming in biofloc more broadly — has grown as a niche because murrel commands a strong market price and tolerates low dissolved oxygen better than almost any other farmed species, which forgives some of the DO swings a young biofloc system produces. Murrel is carnivorous, though, so it doesn’t graze floc for nutrition the way tilapia does, and it needs a protein-heavy feed regardless of floc density. Snakehead are also aggressive and cannibalistic, so uniform sizing at stocking matters more here than with tilapia or catfish.

Matching biofloc fish variety to your system

The right biofloc fish variety depends on what you’re optimizing for: tilapia and shrimp for feed-cost savings through floc grazing, catfish and murrel for high market value at high density, carp only where you have the tank size to support it. Whatever species you stock, biofloc lives or dies on aeration and water chemistry — see the full biofloc equipment range and biofloc fish farming applications page for system sizing by species.