Firstly, it’s been a few days/weeks since I posted. Work etc, you know how it is. So, I have finally established what these little Brown Shrimp are in my sump: Amphipods. It took a while but I got there, and as I suspected, they are good thing. Why? They are classed as detritivores or scavengers and therefore can be considered as part of the Clean Up Crew (CUC). The other plus is that if your water is not in good condition then amphipods will not survive. On a size scale the largest I have seen thus far was about 10-12mm but they can grow to be up to 340mm which would of course have your hand off! Not really! But I might just use a net to get that sucker out! Anyway, the picture is off one of my smaller specimens and measures up at a mighty 6mm.