If you have a rectangular pond with a length of less than 35 meters the smallest model, the 4.0kw will be sufficient. For ponds up to 45 meters the 7.5kw will get the job done. For ponds bigger than this you may need two PondStir’s to achieve the best result. As the mixer size of your PondStir increases so do the arm lengths and counterweight volumes. However, these can be mixed and matched to suit your unique pond. For a free appraisal of your pond please give your local dealer a call.