I worry about the same thing, especially with the cories - they're a bit too curious for their own good LOL (hmmm curiosity killed the CORY cat ???). After the gravel vac part is done I'm thinking of putting a clean knee hi pantihose over the end of the python tube so that water can get in but not fish . Has anyone tried this ? does the pressure just suck the pantihose into the tube ?
35G barebottom: 2 boesemani rainbowfish, 4 congo tetras, Low light plants (1.5wpg) attached to or planted in my own handmade ceramics - Anubia v Nana, Anubia v Barteri, Red Rubin Sword
2.5G - Spot (beautiful betta - Soft pink with red spots on his fins. Java Moss.