Pond net covers are also widely used in aquaculture industry as it is a must for them in order for the fish breeders to protect their valuable stock from damage caused by predators. There are some suppliers that uses fine mesh as these offers the best solution to protect from certain bugs like dragonfly that can lay eggs in idle water and once the larvae hatches, it can consume and hunt down small koi fish fry. At times, koi nets are used to prevent the fish from jumping out from the pond although to me, providing netting is not a long term solution as we need to deal with the root cause of the problem itself. Fish willing to jump out from the water is actually a symptom caused by different conditions especially those related to water quality. Although there is no specific root cause to it, some jumpers are known to contact disease and there are unconfirmed reports that fluke or ich could be one of the culprits. Another possible cause to it could be due to cats that loves to grab the fish in its mouth and toss it out and that might lead you to think that the fish actually jumped out from the water, which obviously is not the case. If this is the real problem to all that we have discussed earlier, then netting is the possible solution to address the issue.
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Pond Vortex filter system and Koi Pond designing tips and instruction