Weekend Gardener

The primary concern of any koi pond keeper, indeed of any fish pond keeper, it to preserve the pond water at a high level of hygiene. This basically means that you have to keep the nitrate and ammonia levels down. However, the fish will not help in this endeavour, and nor can they, since they live and defecate in their surroundings, the water. You can accurately say that the live in their own toilet bowl.