During the COVID-19 pandemic, the use of tarpaulin ponds for fish farming has gained significant popularity among Indonesians. Data from various sources indicate that 60 percent of fish farmers have shifted to tarpaulin ponds due to their cost-effectiveness and efficient land use. One species particularly well-suited for cultivation in such ponds is the pangasius fish (Pangasius sp.).

Tarpaulin ponds have become the preferred choice because they are more economical compared to other methods. The construction and maintenance costs are notably lower, and the materials required are relatively inexpensive. Additionally, tarpaulin ponds are practical and adaptable to a variety of land conditions, making them an attractive option for fish farming.

By utilizing tarpaulin ponds, limitations in land availability no longer pose a barrier to pangasius fish farming. This method allows for cultivation on both prime and marginal land, whether outdoors or indoors. Many fish farmers have reported that raising pangasius in tarpaulin ponds is highly cost-efficient while meeting the consistently high market demand for this species.

To maximize the benefits of farming pangasius in tarpaulin ponds, it is essential to understand and implement proper farming techniques. The following are the technical steps for cultivating pangasius fish in tarpaulin ponds:

1. Selecting the right type of tarpaulin pond

There are four types of tarpaulin ponds available, each suitable for different budgets and locations. Each type has its own advantages and disadvantages, as outlined below:

• Full tarpaulin pond
  A full tarpaulin pond is easy to set up, making it an ideal choice for beginners or those with limited land. Its simple structure allows for quick construction without requiring advanced technical skills. However, this type of pond has lower durability compared to others. It is more susceptible to damage from direct sunlight exposure or abrasion.
• Tarpaulin-lined wall pond
  Ponds with permanent walls lined with tarpaulin offer greater strength and durability. The sturdy walls, typically made of bricks or concrete, provide extra protection for the tarpaulin lining. However, this type of pond incurs higher costs due to the construction of permanent walls, making it more suitable for fish farmers with larger budgets and long-term plans.
• Earthen pond with tarpaulin lining
  This type of pond uses natural soil as the walls, with tarpaulin lining the bottom. It is a cost-effective solution for fish farmers in rural areas, as it reduces the need for construction materials. However, the main drawback is the risk of damage caused by the uneven surface of the soil.
• Instant tarpaulin pond
  An instant tarpaulin pond offers a quick and practical solution for those needing a ready-to-use pond. These ponds typically come in square or round shapes with supporting frames, allowing for fast installation. Their advantages include flexibility and ease of use, but they tend to be more expensive than other types. Additionally, instant tarpaulin ponds are generally smaller in size, making them more suitable for small-scale farming.

2. Constructing a tarpaulin pond

Constructing a tarpaulin pond requires careful attention to detail to ensure smooth and problem-free pangasius fish farming. The steps involved in building a tarpaulin pond include:

a. Selecting high-quality tarpaulin
Choose tarpaulin with a thickness of A5 or A6, which can last up to five years. Inspect the tarpaulin directly to ensure it is free from defects or leaks. The size of the tarpaulin should be adjusted to fit the available land area.

b. Preparing the land
The designated area for the pond should be leveled, and a drainage channel should be constructed in the center of the pond. This channel facilitates water replacement and simplifies the harvesting process.

c. Adding a layer of fine sand
Spread a 10 cm layer of fine sand evenly across the bottom of the pond. This sand layer acts as a cushion to protect the tarpaulin from damage, extending its durability.

3. Selecting high-quality pangasius fingerlings

The selection of appropriate fingerlings plays a crucial role in determining the quality and timing of harvest, as healthy fingerlings significantly enhance farming success rates. According to data from the Freshwater Aquaculture Development Center (BPBAT) in Sukabumi, West Java, Indonesia, high-quality fingerlings are typically sourced from superior broodstock managed using modern breeding technologies. One renowned center for pangasius fingerling production in Indonesia is BPBAT Sungai Gelam, which consistently produces high-quality fingerlings such as the Pustina strain.

Harvesting of 50,000 pangasius seeds, each measuring approximately ¾ inch in Sukamandijaya Village, Ciasem Subdistrict, Subang Regency: Luhkan Kab. Subang/Ali Narli

Characteristics of high-quality pangasius fingerlings include:

• Uniform size: Ensures equal growth opportunities for all fingerlings and reduces the risk of cannibalism.
• Active and undamaged: Vigorous movement is an indicator of healthy physical condition.
• Disease-free: It is essential to inspect for signs such as white spots or lesions on the body to confirm that the fingerlings are free from infections or parasites.

4. Stocking fingerlings in tarpaulin ponds

Once the tarpaulin pond is constructed and its depth confirmed, the first step is filling it with water. Initially, fill the pond with 20 cm of water to provide a controlled environment for the fingerlings to adapt. Gradually increase the water level each day until it reaches the desired depth. This gradual filling process is essential to prevent sudden temperature fluctuations, which could stress the fingerlings.

The acclimatization of fingerlings is a critical step to ensure they adapt smoothly to their new environment. Before releasing the fingerlings, place the plastic bag containing them on the surface of the pond water for 15–20 minutes. This allows the water temperature in the bag to equalize with the pond water, minimizing the risk of thermal shock. Once the temperatures are consistent, gently open the bag and let the fingerlings swim out into the pond at their own pace.

In terms of stocking density, it is important to match the number of fingerlings to the size of the pond. For instance, according to data from Catfish Fabrication, a 1 x 1 x 1-meter pond can initially accommodate approximately 33 fingerlings of 3–6 inches per square meter. Maintaining an appropriate stocking density is crucial for promoting healthy growth and minimizing risks such as oxygen depletion or food competition, which could hinder fingerling development.

Distribute the fingerlings evenly across the pond to ensure each has sufficient space and access to resources for optimal growth. Proper stocking practices significantly contribute to the overall success of pangasius farming.

5. Feeding practices for pangasius fish

According to data from eFishery, the recommended daily feed dosage is approximately 3–5 percent of the fish's total body weight. However, this percentage is flexible and can vary depending on the fish's actual consumption needs. Adhering to this dosage ensures that the fish receive adequate nutrition for optimal growth while minimizing feed wastage.

In Patin Village, the process of producing pangasius feed involves a blend of ingredients, primarily rice bran and salted fish

For juvenile fish, it is advisable to feed them 4–5 times a day. This frequent feeding schedule supports their high energy and nutritional requirements during the rapid growth phase. In contrast, adult fish require less frequent feeding, typically 2–3 times a day. Reducing the feeding frequency for mature fish helps prevent excess feed from accumulating and going to waste.

In addition to the quantity and frequency of feeding, the quality of the feed is equally important. Ensure that the feed contains nutrients tailored to the specific needs of pangasius fish, including proteins, fats, and essential vitamins necessary for their growth and overall health. Specially formulated pellet feeds for pangasius fish usually meet these nutritional requirements.

Proper feeding practices help maintain the fish's physical condition, accelerate growth, and reduce the risk of diseases. By balancing feed quality, quantity, and frequency, farmers can achieve efficient and sustainable fish farming outcomes.

6. Routine maintenance

An essential aspect of aquaculture maintenance is the management of water quality. According to data from Aquair, periodic water replacement recommended every two to three weeks plays a crucial role in maintaining cleanliness and environmental stability in ponds. During water replacement, it is advisable to remove one-third of the water volume from the bottom of the pond to eliminate uneaten feed and waste that may contaminate the water. Fresh water should then be added slowly to prevent sudden temperature changes, which could be harmful to the fish.

In addition, regular monitoring of the pond’s condition is essential, particularly during the dry season, as evaporation can occur rapidly. Data from various sources indicate that high temperatures and intense sunlight during the dry season can significantly increase the evaporation rate, which may impact water levels and overall pond conditions.