Ramon Kourie

Hi Femi Monitoring requires a dynamic approach in that at start-up one needs to monitor nitrites in addition to ammonia (NH3_N), pH, dissolved oxygen and floc volume (Imhoff Cone) where once nitrites stabilize monitoring can exclude nitrites (NO2_N). After three months one needs to be monitoring copper, iron, manganese, magnesium and zinc in addition to nitrates - these become more important to m ...

Hi Sanu Did you include your carbohydrate source in your calculation of FCR's? This would be the most pragmatic approach to take. I would be keen to learn how much you carbon source adds to your FCR. Best Ray

Hi SanuLast comment. It is often erroneously believed that ALL solids require to be kept in suspension in BFT systems raising tilapias. Our BFT design is selective allowing heavier solids (10-20min settlement time in an Imhoff Cone) to drift on the tank floor which enabled their easy removal from the tank system once a day. While floc was less dense at required 30-35min to achieve a terminal readi ...

Hi SanuFurther to my comments above.It would appear that moderate training actually reorganizes metabolism so as to spare the muscle [against muscle loss] in many teleost's including tilapias (Belal, 2015) with the result that protein growth is promoted over lipid growth in fish that are both fed and continually swum (Christiansen et al., 1989; Lauff and Wood, 1997). The Belal (2015) study indicat ...

Hi Sanu. A recent study entitled, “Effect of Water Velocity on Tilapia, Oreochromis niloticus Fingerlings Growth Parameters and Body Composition” (Belal, 2015) looked at horizontal water velocities in fingerling Nile tilapia production. A velocity range of 20-35cm/sec was considered optimal, although lower FCR’s were recorded at a velocity of 25cm/sec as opposed to 35cm/sec where the higher veloc ...

Hi Sanu.We wont try to enhance density as there is a correlation between density and FCR's that was apparent in the Chambo Fisheries BFT tank systems operating at 16-22kg/m^3 (as a function of fish size. Rather through further design optimization the aims are to use less power via a more efficient sub-surface diffused aeration system and elevated horizontal water movement from 20cm/sec to 30cm/sec ...

To all interested Engormix list members. I'm afraid I'm always under pressure and cannot always answer your questions. I am busy writing a book to be called, "A Guide to Tilapia Production in Biofloc Technology (BFT) Systems". I wont be covering shrimp BFT production as there is already a good publication available through the World Aquaculture Society (WAS). My mission is promote tilapia product ...

Hi Harish If you can get 50t/Ha/crop of shrimp using nano-bubble aeration technology then I've got to hop onto a an airplane to see your set-up. I'll be bale to promote your initiatives.

Hi Kolbjorn.I wll look for the Japanese study hen revert. Best, Ray

The trust projected by Prof. Lupatsch is exactly what the aquaculture sector, acrosss all fed species/production systems, would need to be focusing on. Increments in raw material commodity prices particularly over the past 5 years calls for revsions to the way we calculate daily ration on fish farms. FCR's and wate output would need to be optimized for all species/systems and as such the good Prof ...