Eheim slowing down

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Aquarium Advice FINatic
Jul 30, 2005
I have an Eheim 2215 (I think) that has been set up on my 50gal tank for about 3 or 4 months. When we first set it up, it was so fast and had such good water pressure - now it's slowed down to about half of its former speed; the current in my tank is much less.

I have cleaned the filter media every month, replaced the filter wool completely a couple of times, taken out the impeller and cleaned that... but it's still slow. What's going on?

For a few weeks I had my DIY CO2 running through it (tube from the CO2 went into the intake for the filter), and am worried I could have damaged something with the bubbles that would have been in there... how can I check this? If this is the case, is there a part I can buy to fix this?

Thanks for your help!
Well with all pumps, you want to impeller to remain wet at all times, so if you're having a lot of air go into the filter intake you might not be getting the lubrication necessary on your pump. Try emptying out the filter completely and running it to see what kind of flow you get out of it. You might just need to replace some parts to repair the filter.
I have since removed the CO2 so it should be running on water now with no more bubbles. I will try emptying it completely as a test - had thought of this myself earlier. Then I will know whether it's media or mechanic, I suppose. What parts would need to be replaced?
also check the tubing. there was a lot of gunk build-up in my fluval intake tube that had slowed the flow to a minimal.
I've noticed a little gunk build-up on the spraybar holes of my 2215. If too much stuff collects there, flow will certainly be affected. Also check hoses for kinks, that all valves are wide open, that there isn't a plugged sponge on the inlet basket etc. etc.
I thought of another thing. Try to see if everything is balanced in the canister filter. Basically, pumps are designed in such a way that the impellers are trimmed and balanced. I knocked my XP3 around a bit and my motor wasn't turning a balanced impeller. Mine made an awful noise, but it's possible that yours may not make a noise.
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