Impeller ... disolved?


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I have a powerhead that I use to mix kalk (Maxi 600) and it's up off the bottom of a HD bucket on some PVC piping. Runs continuously to stir the kalkwasser mix that I dose at night.

Recently, I noticed the water wasn't mixing much, now not at all. I opened it up last night figuring it had gotten caked and siezed. Not so. The impeller fins are gone. The impeller is undamaged otherwise and the plastic center ring for the fins is still there so it didn't shatter. I couldn't find the fins in the bucket, but I didn't really empty it and sift it, jus ran my fingers around searching for anything hard.

Is it possible for a plastic impeller to disolve/disintegrate in Kalkwasser over time? Or is this a wear issue? I didn't think Kalkwasser would abrade plastic like that.
I would think abrasion is the culprit. The pH should not dissolve the plastic, but Kalk is a slurry and will erode the plastic over time.
My only concern is that I've only had the thing running in there for about 2-3 months. The powerhead wasn't new, but I inspected it and it was fully functional.
Lime Water has a very high PH (12~13). Anything is possible. But I think most plastics are impervious to Acids.

Are you sure you did sniff some paint or something before? only joking.
My bet is the undisolved calk wore down the impeller blades. Kind of like cycling small amounts of very fine sand through the pump 24X7 for 3 months...