Rubber band (Elastic).

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Here are a few more supplies that you should have at home for your Koi fish pond:

Net – A net will be needed to remove your Koi from the water. It might be necessary when preparing for a big storm or just to clean up your pond.

Paint Bucket – Paint buckets are an alternative way (than the net) to remove Koi from the water. Keep in mind the size of the Koi when choosing the bucket.

Rubber Bands – These are used to close the bags with your Koi when you are transporting them.