Hi Donna, I have had similar issues with the RSM stock substrate. When I vacume the substrate, I now put a kink in the hose as I hold it and when I see the substrate raise too high in the pipe I kink the tube to stop the flow untill the substrate drops back down. Hope you know what I mean.
LaurentSeattle - I love your yellow zoa's (middle left of piclure). What type are they? Sorry if they arnt yellow, I'm a bit colour blind
