I'm trying to replace tubing on my FX6 and FX4. I've heard Tetra Pond tubing works well. I've tried it, but the typical band clamps with the barbed fittings allow drips, and I want to go the cement route to join the hose with a barbed fitting (gray plastic, I assume PVC). So far Oatey Flexible Medium PVC Cement has not worked (a slight twist to the joint after a 24+ hour cure caused the hose and fitting to separate). What should cement should I try next? I want to stick with the pond tubing if possible, as it's easier to work with than heavy-walled vinyl hose.