Students completed transfer of Murray Cod and Yellowbelly from 1000l tanks to Aquarium (Lab). Acclimatised fish- time, water temp and water. This leaves Tanks 3-5 available for future 'agistment'. Refilled tanks and sump to 'normal' level. Need to reactivate Biological filter and investigate protein skimmer. MUST grade Trout utilising Tanks 3-5 then transfer back to Tanks 1-3.
The group is meeting at WCS ARC today. This is a strong political group whose mission is to develop, promote and protect a sustainable aquaculture industry for the benefit of all stakeholders & the environment. http://www.ccaf.org.au/
Excess food. Suspended feeding of fish to develop scientific determination of mass of food for each tank. Will purchase scales and conatiners to prepare food each day? Drained and Flushed Sump. Backwashed and rinsed. Adjusted air flow to balance air to Lab and Aquarium.
Murray Cod and also Yellowbelly will be moved to the Lab into Aquarium by students next week. This will allow greater control of their environment and food. We have continued to have significant losses of both species although the Murray Cod have has the most loss.
To extend our species farmed at the ARC 22 Silver Perch were added to the ARC this morning. Transported from Taree by Graham the fingerlings have been quarantined in the Lab section of the ARC using aquariums. After observation a decision will be made to either introduce them to the re-circulation system or continue their time in the Lab.
Yabbies (Crayhaven) moved from the dedicated yabby grow out tank to the Trout tanks. This represents a change from the Monoculture situation (growing only one species in a given area) to Polyculture or Multiculture growing multiple species together. http://www.alken-murray.com/glossarybug2.html The yabbies will consume any of the over feed left on the bottom of the tanks. AND hopefully the Trout will not consume the Yabbies?
System Backwash and flush. Sump drained and flushed to remove waste food etc. Added rain water to Tank 3 to allow it to settle before rejoining Tank 3 to the recirculation System. Added 200g then 500g Bi-Carb Soda (Sodium Bicarbonate) to act as a pH Buffering Agent.
Excess food had been carried into the sump. We need to fit 'socks' to the inlet pipes to filter out solid material such as food and fish waste. The sump was drained as much as possible by continuing the recirculation while tank valves were turned off. Once the water level had fallen below the pump valve the motor was switched off and a hose connected to the outlet valve at the base of the sump. All water and excess food etc. was drained. New water from the rainwater tank was added and the recirculation restarted. Excess food will decompose releasing dangerous nitrates and ammonia into the system.
We have lost 12 Murray Cod in total with 2 more being found today. All dead fish are stored in the ARC Freezer for later examination and measurement. Water tests confirm that the water is healthy. It has been 4 weeks since the fish were introduced. The temperature of the recirculated system is 21.9C. Murray Cod prefer temps from 24-26C. We may have to move them from their current tank to an aquarium to better control the water temp?