This thing gives me so much hassle when i try and prime it The self primer works terrible. I was wondering if theres any tips you guys have on how to prime it?....last time I cleaned it I had to siphon it manually pretty gross

Yeah thats one reason, I dont have one anymore, the silly little primer that comes with that is just stupid.....

the only way I got it to go was to just pump that primer hard a few times and then let it sit to get the water to run all the way down the system, then a few mins later do it again

Alright Thanks. I ended up siphoning it manually again I got so impatient.......I'll be sure to try your advice next time round

I have some Fluval cannisters from the newer 05 series and I gather they've improved the priming system, I've never had any problems with them, they seem to fill quite easily and quickly up to now. Is the self-primer thing gunked up at all?

No it's not gunked up at all, i usually keep all that clean and free of debree. The primer on the 04 series is just a tiny little pump up and down thing......that doesn't work very well at all. What is the 05 series primer like?

It's very similar in design I think - it's a basic idea like you say, not sure how they've improved it but they say they have. I've noticed during routine maintenance that gunk from the input hose does seem to collect in there, must be a bit of a design flaw, but on the other hand I've never had any problems with it not priming or taking very long to fill

You must be a lucky on mrbumblebee, Both my 305's are horrid to prime, it takes so long. and it's exhausting too. There must be a knack to it

Oh that's interesting Peanuts, maybe I am the lucky one after all then. I have a 405 and a 205 and they both fill from scratch in under 30 seconds. If the tubing is already primed, I just open the aquastop valve and it floods in. If I'm priming from scratch including the tubing, I open the valve, push and pull the self primer a couple of times and thats it. If you're having problems it may be worth checking your tubing is straight and taut enough, the aqaustop valve is working properly and is fully open (they can get stuck), that the self-primer thing is not all gunked up and that the ball-stop in the intake strainer is not gunked up either as this is what causes the vacum from the tank side and if its blocked it will reduce the performance anyway