redearslider.com

I have a Fluval 405 filter that stopped gravity filling a LONG time ago with no explanation whatsoever that I can come up with. I even switched it to another tank (swapped the Rena XP3 over to the big tank and the Fluval 405 to the smaller tank).

So even that changed nothing.

It USED TO gravity fill for the first several years and just suddenly stopped.

So now I have to fill it in the sink all the way up and connect it and then it works fine. I don't get that one.... nothing changed... not the hose length or distances (as stated in the manual) geometrically. It just stopped.

It works perfectly, so I can't see the need to replace it. But I'd love to know what on earth changed. It's not missing any parts and I've even replaced some impeller-related stuff (probably unnecessarily but I had at one point lost that tiny black rubber piece that the ceramic shaft needs)

So one of two things is happening.

1. Gravity stopped working where you live
2. You're not going through the proper sequence of close the intake valve then shut off the filter to keep the siphon in the hose primed. Next time you work on it, go step by step through the directions.

If you're currently floating around answer #1 is the culprit. If you weigh the same as you normally do I'd go with answer #2.

Thanks. I'll try that. It's possible that I have not followed this procedure over the years. I wonder why I never have this problem with my new Rena XP3 - I think I always unplug the filter(s) before messing with the valves. It doesn't seem to matter on the Rena. I'll 'watch' and make sure I do it the way you said though. I guess sometimes we don't even notice "habits" Thank you.