Pond Boss Forums GENERAL QUESTIONS Muddy water Muddy Water: Catfish or Clay?

Dense populations of crayfish absolutely can denude a pond of all algae and macrophytes and lead to turbidity issues - like QA I've had it happen to me [and a few clients] multiple times on a mini pond that lacked predators. Once they run out of algae/vegetation they forage the pond basin for, I assume, mayfly/dragonfly nymphs and uneaten pellets and can create significant turbidity issues.

Jar test is a good idea to perform now per others' advice. Collect two jars - place one in darkness [closet] and one in the light [windowsill]. The jar in the closet is meant to determine if your turbidity is due to planktonic algae bloom - if it clears and the one in the light doesn't, that's the origin of turbidity. If both clear up and silt drops to bottom of jar [which I strong suspect will occur] this means you have mechanical turbidity issues [an organism is stirring the pond bottom]. If neither clears up after a few weeks this means you have an ionic imbalance which can be treated in several ways, including alum/lime. I would STILL collect all suspect fish PRIOR to treating the pond with any amendments for lasting effects.

Take photos of your jar tests against a white background before and during the settling process and keep dates handy. We can review the results and consult you accordingly. Again, I'll bet my PB subscription on invasive fish species being the responsible party here, but it doesn't hurt to perform the experiment - all possible data is welcome so we can help you proceed.