Can you use self levelling compound in a fish pond

Not recommended alone, if any damage occurs it will be harmful to aquatic life. If you cover it with visqueen once it’s gone off and ensure that is water tight then it will prevent this.

I’ve built scores of fishponds. I’ve no idea why you’re asking this question but the answer is absolutely not. If you’re looking for a waterproof compound that will not harm Fish, use SBR and neat cement powder in a ratio of 1:1 by volume . When it becomes a uniform colour , it’s dry

I wouldn’t no, it would break up and contaminate water if not break up and fish will take in

No wouldn’t recommend