Maybe someone can clarify some things about these two systems for me! I'm thinking of building a small scale RAS in the future, but was wondering about some points on how the ones used in industry work.
From what I understand, a RAS (Recirculating Aquaculture Systems) is used to rear massive amounts of commercial fish using a very small volume of water. Generally, it has three components: main holding tank, system for solid (waste) removal, system for biofiltration. So my first question is,
1) How does the main holding tank prevent the fry from being sucked into the solid removal system? From what I've read, it looks like the main holding tanks hold both the adult fish AND the fry (they seem to breed continuously in the main holding tanks).
2) What kind of design is in place to remove the solids from the main holding tanks? It can't be just a bunch of overflows. The design must also take into account for fry since massive water flow may not be too good for that. There has to be some sort of water flow manipulation because solid waste must not be allowed to settle in any areas of the tank.
3) If fry are in the holding tank along with adults, then how are they fed? Most fry require plankton for food, but adults require larger sources. In addition, how do you retain the plankton food if water from the main tank is fed to the solid removal system?
These questions still hold true even if the RAS was designed only for rearing fry and no adult fish.
Now comparing RAS to a system where one would have massive amounts of fish tanks lined up and connected (such as those in your local fish store). Generally, each of the tanks in the array would have its own overflow system, where the water would be funneled to one huge sump. There is a crab farming technique that uses this type of system. I think it's deployed in Indonesia. So, with the idea of having these tanks for breeding in mind,
1) How does solid waste removal happen without too much manpower? Unlike RAS systems which run on automated devices, each tank will gain large amounts of waste unless sucked out.
2) If a mesh is placed over the overflow to prevent fry from leaving, that would mean some other system would have to be in place for isolating the fry. I assume it would be better to catch the fry and place them in a kriesel system rather than leave them in the tank array. Is there a better way to isolate the fry? I'm not sure how the system for rearing crabs in Indonesia work. If the fry doesn't leave the tank array, then how would feeding them with plankton work?
3) For adult fish, how does feeding work if the overflow has to be constantly on? The food would just start flowing towards the overflow until it gets sucked out.
From what I understand, a RAS (Recirculating Aquaculture Systems) is used to rear massive amounts of commercial fish using a very small volume of water. Generally, it has three components: main holding tank, system for solid (waste) removal, system for biofiltration. So my first question is,
1) How does the main holding tank prevent the fry from being sucked into the solid removal system? From what I've read, it looks like the main holding tanks hold both the adult fish AND the fry (they seem to breed continuously in the main holding tanks).
2) What kind of design is in place to remove the solids from the main holding tanks? It can't be just a bunch of overflows. The design must also take into account for fry since massive water flow may not be too good for that. There has to be some sort of water flow manipulation because solid waste must not be allowed to settle in any areas of the tank.
3) If fry are in the holding tank along with adults, then how are they fed? Most fry require plankton for food, but adults require larger sources. In addition, how do you retain the plankton food if water from the main tank is fed to the solid removal system?
These questions still hold true even if the RAS was designed only for rearing fry and no adult fish.
Now comparing RAS to a system where one would have massive amounts of fish tanks lined up and connected (such as those in your local fish store). Generally, each of the tanks in the array would have its own overflow system, where the water would be funneled to one huge sump. There is a crab farming technique that uses this type of system. I think it's deployed in Indonesia. So, with the idea of having these tanks for breeding in mind,
1) How does solid waste removal happen without too much manpower? Unlike RAS systems which run on automated devices, each tank will gain large amounts of waste unless sucked out.
2) If a mesh is placed over the overflow to prevent fry from leaving, that would mean some other system would have to be in place for isolating the fry. I assume it would be better to catch the fry and place them in a kriesel system rather than leave them in the tank array. Is there a better way to isolate the fry? I'm not sure how the system for rearing crabs in Indonesia work. If the fry doesn't leave the tank array, then how would feeding them with plankton work?
3) For adult fish, how does feeding work if the overflow has to be constantly on? The food would just start flowing towards the overflow until it gets sucked out.
