to the fish tank . This difference in flow in the two directions gets controlled by two 25mm ball valves sitting either side of this T-Junction . On the DWC side , the pipe splits into a loop with two pips running the length of the canals and meet again at the end to close the loop . Building al loop is important for it balances the water pressure equally over the three outlets of the canals . Each outlet of the three outlets also has its own ball valve to shut down the flow for an individual canal to do maintenance . You probably noticed that the canals don ’ t have bottom drains ? It ’ s very simple , just pull the standpipes and the water will drain .
CONSTRUCTING THE LOOP : Looking at the diagram , “ Plumbing Layout ” previously you will see “ 20 %”. This is the position where your loop will start . The next steps will guide you construct your loop .
• Looking at the diagram , the approximate length of the loop is 2450mm & 1300mm . It is very ; very important to verify these distances on site before cutting these lengths of pipe for it might cost you to buy a whole six-meter length . It is strongly advisable to cut these lengths of FIRST before any other cuttings because the “ off cuts ” can be used to make up standpipes , short joints between components etc .
• Cut lengths of pipe :
• Two lengths of approximately 2450mm ( to be verified on site )
• Two lengths of approximately 1300mm ( to be verified on site )
• Best position to start is in the bottom right hand corner of the diagram ( IBC 2 ) where the loop makes a 90-degree turn .
• Install two , 25mm x 90˚ elbows into the two pair of lengths .
• Now we move to the top right-hand corner of the loop . Cut a 100mm piece of 25mm pipe and insert two 25mm x 90˚ elbows on each side of the 100m pipe . The openings of the two elbows must face the same direction .
• Insert the two lengths of 1300mm pipe into the sockets of the 25mm x 90˚ elbows
• Connect two , 25mm x 90˚ elbows on the other end of the two 1300mm lengths and now connect the two 2450mm lengths .
• The piping might become flimsy to handle
AgriKultuur | AgriCulture so it is advisable to tie the pluming to the cages with cable ties .
• On the top 2450mm length , insert a T-junction with the stem facing downwards .
• Insert a 100mm piece into the stem of the T-junction and now complete the loop by joining the 100mm pipe and the bottom 2450mm pipe with an elbow .
FITTING THE BALL VALVES :
• Cut in a T-junction into the top pipe lengths , 150mm from the IBC ’ s side in the positions as indicated on the plan . The stems of the T-junctions must face upwards .
• Insert a 30mm long piece of pipe into the stem and fit a 25mm ball valve with the tap handle facing outwards .
• Insert another 30mm piece of pipe on the other end of the ball valve and fit a 90˚ elbow facing towards the canal .
• Cut a 100mm piece of pipe and insert it into the elbow . Fit another elbow on the other side of the 100mm tube facing downwards .
• Cut a 250mm pipe and insert into the down facing elbow to complete the tap .
Plumbing the Water Pump :
The pump is situated in the biofilter which also serve as a sump . This is the lowest point to which water of the system drains and from here , the water gets pumped into the two directions ( fish tank and DWC ). Although the system only requires a circulation rate of 2900 litre per hour , the pump has the capacity to circulate 6000 litres of water per hour . The reason for an oversized pump is to cater for future expansion .
It is not a good idea to put strain on a pump by closing the relevant valves to get the desired flowrate throughout your system . Therefore , it is important to provide some form of relieve by installing a “ back pressure ” pipe to return the access water to the sump . Since the biofilter bacteria require dissolved oxygen ( DO ) for the nitrification process , it is advisable to fit a Venturi to this back-pressure pipe . A valve is also installed to control the flow of water . If you consider expanding your system at a later stage , the valve can be adjusted to provide additional flow of water when required .
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