Following on the 2^nd World War a generation of frugal minded people coined the phrase `waste not, want not’.  Having survived the horrors of war: food shortages, irregular supply of basic commodities, etc they knew what it was like to go without, and therefore saved and reused wherever possible.  The 2^nd half of the 20^th Century saw easier life in the West, and the mantra lost its’ significance.  However, as we progress into the 21^st Century the saying is again becoming relevant due to the excessive demand on limited resources by an over populated world. 

 

Accurate feed management has always been important, but recently it has become critical to ensure that feed is being applied correctly, and that the economically best feed is used to minimise wastage into the RAS or environment.  However, no diet is completely digested, and we normally expect around 20% of the feed to end up as faeces.  In a RAS this matter is collected within the mechanical filter ASAP to avoid the reduction of water quality and then dumped out of the system.  Few in the 21^st century would propose that dumping this into the river is acceptable but it is still generally viewed as a problem that needs to be solved.  There is another way to look at this organic material: it is a valuable nutrient source.

 

The mortalities that are removed from fish tanks each day are a loss to the farmer.  However, this is not a complete loss as the corpse is again a source of organic nutrients which also have value.  Viewed in this manner mortalities are no longer a complete loss, just a reduction in value.

 

Another critical area for saving is in the use of electricity.  Not only do we wish to reduce our electrical usage to cut the monthly bill but also to decrease the size of the backup generator we require to keep the systems running during power failures.  In this regard all processes on the fish farm need to utilise energy efficient designs and motors.  Our latest fish farm design incorporates a very low head in combination with extremely efficient pumps.  Visit our website for further information on these pumps.

 

The modern fish farmer therefore needs to develop a plan to utilise the nutrients in the effluent water stream and the mortalities, to turn these into a profit centre rather than merely a problem requiring a solution.  Various options exist, including aquaponics, silage, composting, biogas production and fertigation.  All of these processes solve the problem and create an income stream for the Business.  Furthermore, she also needs to be reducing reliance on electrical power through appropriate designs and efficient equipment.

 

Remember, waste not want not.