Cleaning tanks with small inhabitants

[earhtmother]

I have a 30g tall with neocardinia shrimp of various sizes & small pea size pebble gravel & I'm wondering what the best way to clean it is without committing multiple homicides. I usually use a Python style cleaner attached to the tap but these guys can be too small to see before they go for that long winding ride down the drain.
Also have a 20g grow out tank with a bare bottom for platy fry that I am having the same issue with

 

[earhtmother]

Any suggestions you can offer for cleaning either of these tanks without killing the inhabitants would be greatly appreciated

 

[rlederer]

Python cleaners have a cap with a fine grid you can place over the entrance that will prevent all but the smallest fish from being filtered out. I thought they came with the python. If you don't have one, you can put a piece of screen or cheesecloth over the opening with a rubberband.

 

[Fresh2o]

Rather than siphon out debris, you can use a turkey baster (or similar device) and shoot a jet of water at the substrate to help dislodge and suspend it. The filter (hopefully with a sponge prefilter) can do the work. I rinse out my prefilters about once a week and what comes out of them resembles chocolate milk.