The most important part of aquaculture is ensuring the quality of the water is suitable for the species of fish being grown and nurtured. Good quality water will be reflected in the growth of good quality fish. The fish cannot escape so they depend totally on the environment you provide them with. A poor environment will lead to poor growth and increased susceptibility to disease and parasite infestations. And different fish tolerate different water quality factors. So you need to know your fish!
What are the factors that affect the quality of the water in aquaculture and fish farming? The following features are worth checking out:
- Temperature
- Turbidity
- pH
- Hard or soft water
- Gases such as oxygen, carbon dioxide, nitrogen, ammonia
- Salinity
- Nutrients such as sodium (N), phosphorus (P) and potassium (K)
We will look aT these in more detail.
Temperature
Fish are cold-blooded creatures, so they take on the temperature of the surrounding water. This will affect the way the fish move, breed and grow. Tropical fish require a warmer environment than fish that normally live in cooler waters.
Turbidity
Turbid waters have fine particles suspended in the water. It looks cloudy. The particles can be from solids such as clay, fish waste or plankton growing there. (Plankton is very small aquatic plants – phytoplankton, or animals – zooplankton.) they may form part of the food for the fished – and they also give off oxygen during the day if they are exposed to sunlight when photosynthesis can occur.
In recirculating aquaculture systems, fish waste can be a problem if it is not removed. The fish waste can lead to a build-up of ammonia and nitrites that are poisonous to fish, and increased nitrogen load and also a reduction in crucial oxygen levels in the water.
In order to improve Water Quality Management in Aquaculture, it is important to choose tanks that are easy to clean in your aquaculture system, and we a large range of conical tanks that are ideal for this purpose. In some cases, a lid to keep out any airborne pollutants can be fitted.
PH
pH is a measure of how acid or alkaline the water is. The levels range from 0 – 14 with 7 being neutral. Below pH7 and the water is acidic, above pH7 and the water is alkaline. If the pH value is wrong for your species of fish they grow badly and may even die.
pH monitors can be fitted onto tanks, so that you can adjust the pH by adding acids if the pH level is too high or alkalines if the level is too low.
Hard or Soft Water
Your source of water determines how soft or hard the water is at the start – but you can adjust this. The recommended levels of calcium are between 40-70 mg calcium carbonate per litre. This determines how hard and alkaline the water is. If the water is acidic you may need to correct this by adding the appropriate chemicals.
Gases such as oxygen, carbon dioxide, nitrogen, ammonia
Oxygen
Oxygen is essential for your fish. They need it to breathe, so the level of oxygen dissolved in the water is a critical factor in aquaculture. You can measure the dissolved oxygen (DO) level by chemical or electric methods, but as long as other factors like turbidity control and aeration of your tanks is undertaken the oxygen levels should remain satisfactory.
Carbon Dioxide
Carbon dioxide is a waste gas from respiration – and aeration of the tank water will keep the levels low enough not to harm your fish.
Nitrogen
Nitrogen overload caused by decay and faecal waste and should be cleared by satisfactory aeration of the water in the tank and cleaning the tanks and purifying the water.
Ammonia
Ammonia is toxic to fish and must be removed. The concentration of ammonia is influenced by the oxygen levels, the pH and how alkaline the water is. It is important to keep the levels of calcium carbonate above 40 mg to maintain this and also to keep up a good level of oxygenation of the water. Regular or continuous cleaning of the tanks and purifying the water take care of ammonia build-up.
Salinity
For the aquaculture of seafish and shellfish the water will probably come from nearby estuaries, so will be saline but the levels of salt dissolved in the water need to be checked and monitored. Some species are more sensitive than others to the correct saline levels.
Nutrients such as sodium (N), phosphorus (P) and potassium (K)
These are all present in seawater but you may need to provide them in other waters and keep them at the right level for your fish. They come in compounds, not as single elements.
Enduramaxx Plastic Water Tanks for Aquaculture
There are many things to consider when setting up and maintaining an aquaculture system – and water quality is a critical component of this. Factors include water temperature, turbidity and the removal of waste products. The oxygen content of the water and the noxious ammonia levels as well as aquaculture wastewater treatment.
Enduramaxx tanks have all the features you need to give your fish the environment they must have to grow and flourish. They have been designed to make life as easy as possible for you in terms of accessibility, durability and easy cleaning and removal of waste products, filtering, monitoring and more.
Enduramaxx have been manufacturing high-quality water tanks and water systems for aquaculture production systems for many years. These tanks moulded in medium-density polyethene can be used for aquaculture water supply, wastewater treatment as fish holding tanks. If you would like to discuss your Water Quality Management in Aquaculture needs with our experts, give us a ring on 01778 562810