Additives are one of the most important ingredients to support the success of vannamei shrimp farming. Additives are materials that are used for a specific purpose. In the cultivation of vannamei shrimp, additional materials are commonly used in the process of preparing culture media water before stocking post larvae shrimp (PLs), managing culture media water, and managing vannamei shrimp feed. The provision of these additives is intended to accelerate the growth of shrimp and improve the condition of water quality used as a medium for shrimp culture.

1. Preparation of aquaculture media

Preparation of media water is carried out for 1-2 weeks starting with filling water into the pond. Preparation of water for cultivation media aims to ensure that when the fry is stocked, the fry can live and grow well. The first thing to prepare, of course, is a cultivation pond. Aquaculture ponds are usually made with a depth of more than 150 cm and have an inlet.

The initial stage in the cultivation media water preparation activity is the sterilization of the culture media. The water used for vannamei shrimp culture is sterilized seawater. Water entering the pond must be filtered using a filter installed at the inlet to a surface height of 120-150 cm depending on the shrimp farming system being carried out. In the sterilization process, 60% chlorine is used at a dose of 20-30 mg per liter. This dose can be adjusted according to available seawater conditions.

The use of this dose can be done if shrimp culture is carried out in very clean waters (rocky waters), far from industrial waste pollution and sources of pollution from household waste (rivers), so that the possibility of the presence of disease-carrying hosts and suspended particles in the water is very small.

2. Vannamei shrimp feed preparation

The formation of natural feed is carried out after the media water has been sterilized. Growing natural feed in media water is absolutely necessary, apart from being a source of feed, it is also used as a green shelter to reduce the intensity of light entering the pond, so that temperature fluctuations that are too high can be avoided so that newly stocked shrimp do not experience stress and can cause death. The application of additional materials is done by dissolving the additives with water and spreading them evenly throughout the pond area. Additional materials used in the form of probiotics, Phytoplankton stabilizer, mineral supplements, and water color. Phytoplankton stabilizer is an additive that contains nutrients, functions to optimize growth and stabilize beneficial Phytoplankton in the pond, control watercolor, help stabilize temperature and pH in the pond ecosystem. In media preparation, the Phytoplanktons stabilizer was applied three times with a dose of 1 mg/L.

3. Probiotics

Probiotics are additives that function to improve environmental conditions. Probiotics were applied only once in a water preparation at a dose of 0.1 mg/L. The application of probiotics is very good to do because this probiotic will decompose organic matter that causes high levels of toxic gases in water that are harmful to shrimp. This probiotic can also be applied as an effort to trigger phytoplankton stabilizers and water coloring.

4. Phytoplankton stabilizer

Phytoplankton stabilizer is used to stabilize the condition of plankton in the water and is able to support the growth of plankton properly. The availability of plankton in this water can be used as a natural food or as a green shelter for cultured shrimp. Nitrification is a trigger for nitrification in shrimp ponds. The use of nitrifiers is to provide a suitable space and environment for the growth of nitrifying bacteria, especially Nitrosomonas sp and Nitrobacter spp, to increase the efficiency of the use of nitrogenous wastes such as ammonia and Nitrite in the pond, to increase productivity by increasing the carrying capacity of the pond, and to create a healthy and balanced environment in the pond ecosystem. The composition of the additives is as follows:

Table 1. Active ingredients

5. Mineral supplements 

Mineral supplements function to increase alkalinity, increase the availability of important minerals in ponds, increase acid-base balance and osmoregulation for shrimp, and support enzyme and hormone activity in shrimp. In the preparation of media, mineral supplements were applied two times at a dose of 1-2 mg/L.

The use of mineral supplements will provide the minerals needed by the shrimp at the time of molting, namely to harden the carapas, besides that this mineral supplement serves to stabilize and even increase the alkalinity so that it is able to support changes in water quality in the culture media, especially the pH of the water. The use of nitrifiers aims to encourage the nitrification process by decomposing bacteria so that organic waste from shrimp metabolism and other waste sources can be broken down into non-toxic compounds.

6. Water colour 

Watercolor is a material used to give color to water. Giving color to the water is done to reduce the intensity of light entering the pond and as an effort to protect the fry when they are just stocked. This watercolor can be used as an alternative to protect fry if the Phytoplankton do not grow or the plankton density is low. In media preparation, watercolor was applied twice at a dose of 0.02 mg/L. Media water is ready for frying when it is overgrown with Phytoplankton. Visually, the media water will appear greenish (green algae) with a brightness of 30-40 cm.

7. Molasses

Improvements in water quality by the application of additional materials are also carried out by the application of molasses. Molasses is one source of organic C that can be used to increase the C/N ratio as an energy source for beneficial bacteria (probiotics) in pond water. This molasses does not directly affect the water, but is used by decomposing bacteria as a source of nutrients and energy to carry out the decomposition process. The amount of molasses stocked every day changed according to the amount of feed per day given to the shrimp.

The application of these molasses will also result in a decrease in the pH of the water, so liming is necessary to increase the pH of the water. Liming is carried out when the pH of the medium water is low (acidic) which is < 7.0. Liming is done using Dolomite at a dose of 5-15 mg/L. Dolomite is used because this type of lime can react directly in water and does not leave waste. The chemical composition of lime used is MgO 20%, CaO ± 30%, and 95% mesh 100 passes.

8. Vannamei shrimp feed management

Feed management in vannamei shrimp culture must be carried out properly because feed is the most important element that supports the growth and survival of shrimp. Biologically, the feed consumed by shrimp is directly processed in the body. Nutrient elements or nutrients will be absorbed and used to build tissue and meat, so that growth is faster. The speed of shrimp growth rate is strongly influenced by the quality and quantity of feed provided and environmental conditions. If the feed provided is of good quality, sufficient quantity, and supportive environmental conditions, it is certain that the shrimp growth rate will be faster as expected. Feed that will be given to shrimp can be mixed with additional ingredients in the form of vitamin C and mixed with commercial adhesives or egg whites. Vitamin C is one type of vitamin that is easily damaged when exposed to heat and is easily soluble in water.

Vitamin C can increase the body's resistance to disease, prevent body deformities, prevent environmental stress, accelerate wound healing and increase the growth rate of shrimp. The application of additional ingredients to feed in the form of vitamins starts from the first month and is given periodically, until before harvesting. Doses that can be used range from 3-4 grams per kilogram of feed and are given every 3-4 days, and the frequency of feeding is 1-2 times per day. Other types of feed additives (multi-vitamins) in the form of liquids or emulsions can be applied directly mixed with artificial feed with doses according to the rules.