What’s the best return pump for 29 bio cube Aio ? I currently have a IM mighty Jet midsize but have issues with impeller stalls during middle of night. It seems like the white disk on front by impeller seems to not move freely to allow impeller to move freely. I soaked in citric acid etc finally frees up then happens again a day or 2 later. I can’t seem to find the impeller itself for sale anywhere. So I’m looking for something like it but more reliable. The pump is only 6 months old . Thank you for any help!