Operating an aquaponic system
Basic system maintenance and operation procedures
To ensure that the aquaponic system is running well one should prepare clear operating, maintenance and troubleshooting instructions (manuals), and also checklists of daily, weekly and monthly activities for which records should be kept. This way, different staff members will always know what to do. All observations and tasks performed need to be entered (with specific dates) in a dedicated record book, that must be stored in a visible place. It is especially important to record the chemical and physical parameters of the water, and any changes in the appearance and behaviour of the fish (score sheet). Table 9 lists basic system maintenance and operating procedures.
Table 9: Basic system maintenance and operating procedures
| Tasks related to… : | Daily | Weekly | Monthly | Extra |
|---|---|---|---|---|
| … fish feeding | Feed fish twice a day. After feeding, check how much feed has been eaten. If there is uneaten feed, reduce the amount at the next feeding | Weigh fish every 1-2 months and adjust the amount of feed according to the feeding rate suitable for the size of the fish | In case of a system malfunction stop feeding immediately | |
| … fish behaviour | Check if all the fish are alive. Use a score sheet to evaluate their behaviour during experiments | Have the contact information of your veterinarian accessible at all times | ||
| … ensuring water quality for the fish | Check the colour and the smell of water. There should be no sludge in the fish tank | Analyse the water (T,+ -pH, O2, NH4 , NO2 ,-NO3 ). If the levelsexceed threshold values, take appropriate action:
| If you notice anything unusual, immediately analyse the water. Take action, but bear in mind that fish do not like quick changes. Occasionally clean the fish tank and avoid using chemical cleaning agents | |
| … growing plants | Observe the plants for signs of pests and diseases. Remove leaves with signs of disease or pest infestation. Remove dead leaves. If you detect pests or disease, take action(see |
System failures and emergency systems
The use of pure oxygen as a backup is the number one safety precaution. The installation is simple, and consists of a holding tank for pure oxygen and a distribution system with diffusers fitted in each tank. If the electricity supply fails, a magnetic valve pulls back and pressurized oxygen flows to each tank, thereby keeping the fish alive. The flow sent to the diffusers should be adjusted beforehand, so that in an emergency situation the oxygen in the storage tank lasts long enough for the failure to be corrected in time. To back up the electrical supply, a fuel driven electrical generator is necessary. It is very important to get the main pumps in operation as fast as possible, because ammonia excreted from the fish will build up to toxic levels when the water is not circulating over the biofilter. It is therefore important to get the water flow up and running within an hour or so.
If there is a power outage, always follow this protocol:
Check the power lines
Check the electric fuse
Do not add fresh water. This will kill your fish by raising your pH and transforming NH4 to NH3
Do not feed the fish under stressful conditions
If there are either pump and/or aerator system failures, follow this protocol:
In case of pump failure, replace the pump with a spare
In case of aerator failure, replace the aerator
Do not feed the fish under stressful conditions
Do not increase the water flow
Protocol in case of leaks:
Stop the water flow
Check the pipes and valves
Replace the leaking part
Replace the lost water
Do not feed the fish under stressful conditions
Copyright © Partners of the Aqu@teach Project. Aqu@teach is an Erasmus+ Strategic Partnership in Higher Education (2017-2020) led by the University of Greenwich, in collaboration with the Zurich University of Applied Sciences (Switzerland), the Technical University of Madrid (Spain), the University of Ljubljana and the Biotechnical Centre Naklo (Slovenia).