In Ca Mau province at the southern tip of Vietnam, Huynh Ut Nho, who has 13 years of shrimp-farming experience, secured three consecutive profitable crops with a "low-density, water-treatment-focused" style of farming that does not maximize yield, and the family's total profit in 2025 reached about 3 billion dong (3 ty dong; at about 170 VND to the yen, about 17.6 million yen, about US$120,000). This stability, where the numbers did not collapse even in a year of rough prices, is material for Japanese importers and trading companies—who value "not being cut off" over "volume" in Vietnamese shrimp procurement—to rethink the yardstick for choosing an origin.
Huynh Ut Nho held density down across 4 ponds and 3 ha, and retained 3 billion dong a year
The setting is Tan Hung Dong, Ca Mau province. Nho's farm has four ponds totaling more than 3 hectares, with an initial investment of over 2 billion dong (2 ty dong, about 11.8 million yen)—a midsize family operation. Its feature is that it swings fully toward a design that readies the water before gaining pond area. A crop that swings to a large size of 17 pieces/kg in one cycle yields a profit of 800 million–900 million dong (about 4.7 million–5.3 million yen), but not every crop stretches that far. Stacking these large crops and average crops across 4 ponds and 3 crops a year, the family retained about 3 billion dong in 2025.
Vietnamese shrimp farming commonly packs 200–300 pieces per square meter in a high-density, high-turnover style; when it hits, it is big, but if disease wipes it out, the whole investment vanishes. What Nho chose is the reverse idea: lowering density to lower the ceiling profit per pond, and in exchange betting on eliminating the years that fail. What has value from the procurement side is this very structure of "the ceiling is modest, but the floor is predictable."
The TLSS model allocates area not to grow-out ponds but to reservoirs and water treatment
What Nho adopts is a method called the TLSS model advocated by the feed and technology firm Long Thang. Whereas the conventional type devotes most of the site to grow-out ponds, TLSS prioritizes allocating area to reservoir ponds (ao chua) and settling and purification ponds (ao lang). The original article explains this difference as "whereas the conventional model devotes most area to grow-out ponds, TLSS prioritizes area for water storage and water treatment."
The idea of preparing water in advance is plain but directly connected to supply being hard to cut off. When a pond's water quality collapses, whether or not you always hold treated water at hand that can be swapped in immediately changes the judgment on emergency shipments and partial harvests. Nho watches dissolved oxygen, harmful substances, and algae conditions daily and responds in the order of water exchange first, then stronger aeration, then dosing beneficial microbes (vi sinh). With an operation that prepares the environment before hitting with drugs, he holds down both dosing costs and drug residues.
From 600 post-larvae/m² to 100–120/m²: two-stage farming curbs EHP damage
The farming method is two-staged. First, in a nursery pond (uong/gieo), post-larvae are raised at a high density of about 600 pieces/m² for 30–40 days, and after assessing their condition, they are moved to the main grow-out pond and dropped to 100–120 pieces/m². Because resources are committed only after confirming survival, rather than putting the whole batch into the main pond from the start, damage can be localized even if some fall ill.
The direct reason for taking the plunge to low density lies in the experience of suffering a blow from an outbreak of the microsporidian EHP (which inhibits growth of the hepatopancreas). Nho says, "sparse stocking lowers environmental load, curbs disease, and cuts drug costs." Lowering density stabilizes the water quality of each pond and slows the speed at which pathogens spread. As a result, the FCR (feed conversion ratio) is 1.3–1.35, dropping to 1.1 in good crops, keeping a level that does not look inferior to high-density types even on feed cost.
FCR around 1.3 and 17–20 pieces/kg are the stability signals Japanese procurement managers should read
What Japanese seafood buyers dislike most in Vietnamese shrimp is not price itself but "the promised size and volume not arriving in the promised week." Processing and restaurant sites live by yield and specification, and if 17 pieces/kg and 20 pieces/kg are mixed, or the harvest shifts due to disease, both cost and shelf allocation collapse. What Nho's numbers show is the reproducibility of aligning size at the large 17–20 pieces/kg and running predictable production for three consecutive crops.
This viewpoint overlaps with another move underway in the same Ca Mau. The effort that the EU and an NGO are verifying over 42 months, whether Ca Mau's "low-emission shrimp" becomes proof for procurement, is a trend to turn environmental performance into export credibility, and TLSS's emphasis on water treatment can become its groundwork. The idea of extending value through how land is used is the case in Thanh Hoa that raised the value of the land 1.5–3-fold by co-culturing giant freshwater prawns in paddy fields and is close in direction. In real demand for Japan, as with Vietnam Clean Seafood's move to make its first shipment of sashimi-grade tilapia fillets, producers who can promise specification and quality are beginning to be chosen.
Three conditions to confirm before volume in procuring Ca Mau shrimp for Japan
Translating Nho's case into a procurement yardstick makes the points to look at when choosing an origin and farm concrete. The table below lines up the conventional high-density model and the TLSS-type low-density model on the items Japanese buyers care about.
| Comparison item | Conventional high-density model | TLSS type (low-density, water-treatment-focused) |
|---|---|---|
| Stocking density (main pond) | Around 200–300 pieces/m² | 100–120 pieces/m² |
| Use of the site | Maximizes grow-out ponds | Prioritizes securing reservoir and purification ponds |
| Disease / total-loss risk | High (big if it hits / total loss if it misses) | Low (two-stage farming localizes damage) |
| Supply stability | Prone to swing crop by crop | Predictable for three consecutive crops |
| Size uniformity | Prone to variability | Aligns at 17–20 pieces/kg |
In practice, there are three points to confirm in origin interviews. First, the ratio of reservoir and purification ponds to the site. A farm thin here is prone to halting shipments when water-quality trouble arises. Second, the survival rate and size distribution of the past three crops. Look at whether they can be aligned consecutively, not a one-off best. Third, the response history and dosing records for major diseases such as EHP; whether disease is held down by the environment rather than relying on drugs connects to the trustworthiness of traceability. By keeping farms that satisfy these three conditions as candidates before price negotiation, you can crush the hidden costs of shortfalls and out-of-spec goods in advance. The more the exchange rate swings toward a weak yen, the more the uninterrupted-ness of supply, rather than cheap unit prices, governs the real profit of procurement.
