Glad I saw this. My 306 is having similar issues. On my 75 I have the 306 and a 305. The 305 (and my 405 in another tank have very strong flow) but the 306 is weak like in your video. I cleaned everything aka took my garden hose to it, and the flow did not improve at all. So a few days later I took out all my floss and those polishing pads out. The only media in it is the ceramic rings and those tall pre filter pads......and still a pitiful flow. So should I take the pre filter pads out?
Edit: Oh the 306 is only 6 months old. While the 305 I have had up and running for probably 6 years.
I'm not going tell you what to do, I'm just testing a hypothesis
FWIW, I removed the long pad that's farthest away from the stack of trays (along the wall of the canister). I left the one closer to slow the flow trying to bypass into the trays so it flows down and back up through the stack of trays.
While I don't have the low flow problem you have, I do have a tremendous amount of particles settling in the aquarium, more than any other filter I have ever had. I agree with you that there is a lot of bypass with this filter.
Yup, my 30 gallon with an Aquaclear 50 had far less debris, this is a 57 gallon with a filter that's far more powerful. I had almost gotten used to it until I was looking at old photos and I recalled never having debris on the leaves. It makes it look like I have a BBA outbreak until I shake the leaves and it moves into the water column a day after a 50% water change…
Forgive me for saying so fella, but that cover does not look all that flat to me. Does it rock from side to side when you press down on the sides away from the hinge and clip?
PS. Given up fiddling with mine. Flow had gone low again today, when I checked the impeller cover was out of shape again. I think this is a design fault, the cover being secured at only two points. In all other filters that I have had in the past that cover is held VERY firmly in place. I brought this filter because of the amount of time I was spending servicing my two ancient Sera 900s. I'm spending more and more time faffing around with the 406. Nufs e nuf. I'm going for a Ehiem Pro 600.
It looked straight to me, it's hard to assess how flat it is because the cover has clips and protrusions that keep it from sitting flat on table to test. I will take it out again and take another look.
It didn't rock when I reinserted it from memory but I'll do a quick check and see if it rocks - I'm not a fan of having to heat and cool a piece of plastic with rubber over and over again - this sounds like a recipie to weaken the piece and structural failure.
That being said, if it's common issue then it's is a design flaw - How do these guys keep making equipment over 20 years and can't get stuff like this right? It's not like rocket science or brain surgery, it's a water pump in a canister... Sigh
This may be the last piece of Fluval equipment I purchase. Makes me think the ADA stainless steel filters are worth the millions they charge, LOL
I’m considering a Eheim 2217, SunSun, or a CFS-500 (they apparently fixed the flaws in version 2).