I have another thread about my recent disaster with my Fluval 407, but I had a mostly unrelated question so thought I'd make a different topic. I've always run my 407 at max flow with a spray bar underwater to reduce surface disruption in my CO2-injected planted tank. After my previous one failed and leaked everywhere, I've purchased a replacement, but when I turn it on max flow, the plastic end cap keeps popping off. I can reduce it to about 60% and it will stay on, which is still safe according to Fluval (up to 50% is ok), but I'd prefer to keep it on full flow. I've seen many people with similar issues just superglue the end cap on, but in reading up on it, the end cap is supposed to be a pressure valve that pops off if the pressure is too high. Given that a power outage lead to the leak in my previous filter and my concern about possible pressure issues, I'm a little leery of supergluing it. Does anyone have any hesitations about that? I'm going to sit down and clean out the interior of my spray bar tonight to see if that helps, but if not, I'd be interested in hearing what the community says.