When we started this business, we couldn't gather the proper information about biofloc fish farming. Although we had completed our costly one day training from a "self-proclaimed" know-it-all trainer, we were still in the dark about a lot of stuff related to this aquaculture technique. So, naturally we faced a cluster of problems which seemed insignificant to us because of our lack of knowledge.
 |
| Yeah. We failed to plan properly. 😔 |
That made us realize that most of these problems are not addressed by the novice trainers during the short training span and most beginners will face several of those problems. In this post we are going to try to address as many problems we can, so that beginner agriculturists do not have to face the problems we did.
Problems faced in the early stages :
- Maintenance of the floc
- Mortality of fish seeds during transportation
- Sanitization of fish seeds before releasing them to the tank
- Ammonia spike in the first few days
- Formation of foam on the water surface
- Problems due to sudden temperature drop
We'll try to briefly explain them.
Maintenance of floc :
 |
| Source: LINK |
When we are preparing the water in the tank before the arrival of the fishes, we add a required amount of probiotics powder with a carbohydrate source, like molasses and keep the tank running for about 3 days before we add the fish seeds. The formation of the floc happens during these few days. So we should keep the aeration on so that there is vigorous water movement because the floc needs to be in suspended state in the water. The dissolved oxygen (DO) must be checked because the bacteria need oxygen for their survival. Temperature of the water should be maintained above 20℃. A rule of thumb is to release the fishes within 60-72 hours from the time of inoculation (addition of the probiotics) otherwise add some fish food so that the bacterial colonies survive.
Mortality because of transportation :
 |
| Fish seeds oxygen packed in poly-bags for transportation |
When we go to buy fish seeds (juvenile fishes which we are going to rear) from breeders, we either get them delivered to us by transportation or we can carry them personally. Every time we got new fishes delivered to us or even if when we went to buy them ourselves, there were a lot of casualties. We were actually panicking because we thought that we must be doing something wrong which was causing the fish moralities. Now we know that some fishes will die during transportation. This is mainly caused by stress in the fishes because of the whole ordeal and also because of lack of DO in those packed plastic bags. We have noticed the mortality rate is somewhere between 2-5% in most cases.
Sanitization of fish seeds before releasing them to the tank :
 |
In the first few cultures, we used to bring the fish seeds and then happily release them to the tank. Hardly did we know what mistake we were making. Actually the thing is that these juvenile fishes usually carry a plethora of pathogens and parasites. So, it is very very important to sanitize them first before releasing them to the tank.
I use a solution of 1 gram of Potassium permanganate powder in 20 litres of water to sterilize the fish seed before releasing them in the tank. This helps in getting rid of the unwanted pathogens that the fishes carry with them. I do it by taking the fishes in a net and dipping them in the solution for about 10-15 seconds, and then dipping them in clean water and then releasing them. I have noticed that this process helps in getting rid of many extremely lethal parasites like Ich.
Ammonia spike in the first few days :
 |
| Level of ammonia is 8 ppm |
Biofloc technology is a high density fish farming technique, we can say that we intentionally overstock the tank critically. After the release of the fish seeds, the fishes are under stress caused by numerous reasons. Hence they do not consume food in the first few days or consume food less than usual. This leftover food and sunken dead fishes causes a massive increase in the ammonia levels in the tank because the floc is not yet that active or maybe because of less than adequate floc in the water.
A simple but temporary solution to cope with the ammonia spike is to add carbon source like molasses or sugar in a controlled way. This is not a permanent fix, just a temporary solution.
Formation of foam on the water surface :
 |
| Source: Facebook |
You can see thick white foam in some biofloc tanks. This may look alarming but it is actually not that big of a deal. This foam is caused when we add more probiotics weekly for the maintenance routine. A proper aeration will help you a bit. Instead of adding the probiotics weekly, you can try setting up a FCO tank. This eliminates the foam on the water surface.
Problems due to sudden temperature drop :
 |
| Too cold? |
Fishes are cold blooded creatures i.e they regulate their body temperature with respect to the temperature of the water they're swimming. Hence fishes find it difficult when there is a sudden change in temperature. If the temperature is below 20 degrees they will get lethargic and stop accepting food and die eventually. To know more click 👉 here.
