Freshwater Plankton Case Study
Freshwater treatment for AGD requires checking for few things before and during the treatment to carry out a successful and effective treatment.
1. Freshwater Source: The freshwater source should be checked for temperature, total ammonia nitrogen and ammonia percentage, pH, hardness, salinity and any harmful plankton.
Temperature: Freshwater with temperature closer to the temperature that treating fish are being reared in is best choice. Colder the water better as higher temperature also plays a role in increasing the toxic ammonia concentration in the water. Temperatures below 15oC are preferred but up 20oC would be acceptable. If possible using chillers the water temperature should be brought …show more content…
Softer the water the better for treating fish. So, checking for these and selecting softer water would be of great help.
In general freshwater tend to have some salts too attributing some lower salinity readings. To ensure effective AGD treatment, the used freshwater should have a salinity of less than 3ppt. So, intake water should also be checked for salinity.
Plankton is present in both freshwater and saltwater environments. Some of the freshwater plankton produces toxins and would be harmful to fish. So beforehand, water at the source should be checked for presence of any harmful plankton.
2. Saltwater, when compared to freshwater is more complex and harder to control most of the properties as it may lead to desirable or undesirable changes. Unless absolutely sure it is better not to try to change saltwater parameters. Saltwater should be checked for few parameters before getting the water on board if using a well boat for treatment. If tarp system is being used, it is still wise to look at following parameters in the adjacent waters. These parameters include temperature, TAN, pH, other gas concentrations and harmful …show more content…
Near bottom waters would have higher TAN concentration because of decaying organic matter on the bottom. These waters would also generally tend to have lower oxygen concentrations and higher salinities. When natural upwelling events happen, these colder, high TAN and low oxygen waters would be brought up to the surface. Majority of this TAN would also be in the form of toxic unionized ammonia NH3 as pH of the water would be higher in saltwater environment. So, care must be taken not to draw these waters. Water should be analyzed before drawing any seawater