In aquaculture as it is with other livestock management, the most important factor for fry survival is their habitation. It is the most determinant of success in fish breeding. Fish performs all their bodily functions in water. Fish cannot survive in a poor condition much as they can survive outside it. They depend on the water to breathe, feed, grow, excrete wastes, and maintain salt balance. Understanding the physical and chemical qualities of water therefore is a critical to successful catfish production.
By habitat I mean a conducive environment for fish. A place that provides quality foods, water and shelter for your fish for their survival. This responsibility is the sole duty of the hatchery manager as the failure on this part has a grave consequence.
Recently, I discovered how important water pH is to fish survival. Although, I have being in the line for years, it has never really occurred to me how a variation of 0.5 could inhibit my success. Although other factors were dully observed during the spawning but my negligence of this important water factor got me grounded. This is the reason I am writing this to serve as an eye opener to other breeders. As a breeder, I must say that you need and will always need a pH meter or test kit. What a stethoscope is to a medical doctor is what pH meter is to a breeder or farm manager no matter your experience. It is a factor you don’t assume.
PH is the quantity of hydrogen ions in water. It is what determines if your water is acidic or base (alkaline). The acceptable range for fish culture is normally between 6.5-9.0. Though all other factors present – Dissolved oxygen, etc., the chance of fries survival in a low pH water is very low. In my experience a pH below 6 is disastrous to fry. It is worst of when other chemical substance like feeds are been Introduced. This is a major reason why some breeders suffer losses as soon as they start feeding their fries. The pH quickly depleted and the fish died a natural death.
This is why I recommend a pH meter to be kept handy by farm manager. The good news however is lost pH can be restored. Through the introduction of limestone or other natural material containing calcium carbonate you can restore your lost ph.
Limestone is a kind of calcareous rock that contain high levels of calcium carbonate so they are really ideal for increasing pH for either saltwater or freshwater aquariums. While these are generally used for landscaping and can be found in construction stores, limestone is a great way to cheaply and effectively stabilize the pH in your tank.
Other readily made materials are equally available but care most be taken in applying them.