This is for installation in Subang Jaya to modified the siphon outlet due there is too much inflow.
1. Either make a restriction like this below :
2. Try adding an elbow with a short 3 inches of 25 mm PVC with final horizontal incline towards fish tank. No other changes to existing pipe just add to make an incline with second elbow as below.
Please try ... the pump used was slightly higher capacity, since 2 growbed involve, and unbalance will cause the other growbed to receive more that its fair share of the inflow.