The 15000lt outdoor pond I am currently building will be equipped with waterfall pump and a filter for running this koi pond. Any suggestion on the capacity of waterfall pump/filter. Would it be sufficient if I just install the waterall pump and without the filter. Pls. enlighten me on this. I will be keeping 5 young (4inch) kois, would if be right if I add
mature ones too in the future as I worry the young ones might be bullied by the larger ones. Thanks once again for answers.


As for the water fall pump you can use a 300- 400 gph pump to power your water fall depending on how much water you want rushing down at all times. As for hooking the pump without a filter it will work for aerating the water but wont clean and stabilize the water unless you densely plant the water fall.(and that takes a while to establish) Your best bet is hooking up a filter to the outlet for your water fall so that all the water being circulated is being filtered. If you dont want to buy a filter you can always just make one out of a rubbermaid container ( thats what I did……….works fantastic for about 25$)