Aqua Clear Filters - When to Repair/Replace?

  • We are currently upgrading MFK. thanks! -neo
LMAO, no wonder your impellers are constantly getting gunked up, as you put it (reduced flow rate = more sheet sticking), and no wonder you are constantly removing them, cleaning them, and replacing them every few years. You failed to mention that factoid in the other recent AC discussion.

Yesiree, you are clearly saving money! lol
No, you are wrong. Smaller impeller has smaller blades, turns faster, and gunk up slower. It pumps less water but a lot quieter. Not all my replacement impellers are down sized, only in tanks with oversized filtration that slower flow is desirable. I only need to clean the impellers every 3 to 4 months or before I leave for vacation.

AC is definitely the power king of all hobs. It pumps more flow than comparable hobs. It can even continue to pump water in WC when the tank level is half way down. But I don’t need the high flow, and prefer quieter operation. Slow flow also provides better mechanical by capturing more fines in the filter pads before overflowing. All hobs provide more flow capacity than media capacity.

Because of the high power, AC impeller probably doesn’t get gunk up that required cleaning as often as other brands. But cleaning A C impeller is PIA requiring removal of the motor, and risking damaging the O ring seal. I don’t know why AC designed it that way All other brands I know of have sealed motor.
 
No, you are wrong. Smaller impeller has smaller blades, turns faster,

Induction motors like these are usually synchronized to the frequency of the mains supply minus a few percent. So, changing the impeller has no significant impact on on the RPM, It will be spinning at some fraction of 50hz in the US or 60hz in places outside the US with 60hz mains supply.
 
Induction motors like these are usually synchronized to the frequency of the mains supply minus a few percent. So, changing the impeller has no significant impact on on the RPM, It will be spinning at some fraction of 50hz in the US or 60hz in places outside the US with 60hz mains supply.

No, you are referring to direct drive propeller. These are magnetic coupled propellers that will slip if the resistance is built up. This is why a gunk up propeller will stop, and substituting a larger propeller will not work. But with a smaller propeller, there is less resistance and less slip, allowing it to turn at full speed even partially gunk up.

The motor will always turn at the same RPM synchronizing with the current frequency.
 
Thanks for the many responses but there is one question that I have still unanswered:

I have the odd old filter that runs for a few minutes and then stops unexpectedly. I take a toothpick and give the impeller a hit and away it goes for a few minutes and then quits again so I am not using those. Does the actual motor start to act up before burning out?


Would the consensus then be that it is likely NOT the motor in this case and I should just replace either the impeller or the shaft or both? I have had these filters get to the rattling stage before but this is the first one that operates intermittently.
 
Could be the impeller shaft, a slight nick/groove from a single grain of sand could cause that. Impossible for anyone to say without actually holding the parts in their hand, and testing themselves. When these motors fail, I believe that they will fail completely, not randomly stop & start. I could be wrong though, there's always a first for everything.
 
I think the motor is fine. The impeller is shot. I have not had one magnetic drive motor died on me, which included several brands and 20+ years old. Magnetic drive motors don’t get stuck and burnt out, but the impeller has finite life as they get stuck and worn out. I bought several used filters in auction with no concern for performance,,but always replaced with new impeller. Once shot, the only remedy is to replace with new impeller. For AC, replace both the impeller and the shaft which is likely crooked. The shaft can be pulled straight out with a plier. Then put back the motor and watch carefully there is no leak on the O ring, or best, replace with new O ring.
 
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I think the motor is fine. The impeller is shot. I have not had one magnetic drive motor died on me, which included several brands and 20+ years old.

I have. 3 fluval 404s. They'd just stop... Randomly rattle a little. Brand new impeller, shafts, covers etc and no change. Even swapping bits from other working ones just in case the new bits were faulty.
 
the only prob I have had with the AC is when running sand. impeller chamber and sand do not mix. I do not suggest running any impeller than what the filter specked for, and the slower flow rate being better mech filtration I do not agree with. canisters are a better bio filter do to there slower flow rate and large media, HoB are better for mech filtration do to there higher flow rate. AC filters can be good for both, but they will never be better than a good canister for for bio filtration. I have always preferred to run both, the AC removes more particulates there by not having to clean the canister as often long as you clean your AC sponge out every water change, which is easy. allot easier than a canister.
any ways that my 2 cents.

on a side note if you do not like noise do not get a bird.
 
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