Fluval FX4 problem

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Jacky12

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Today I cleaned the two big canister Fluval FX4 that came with a used 125 G. One filter wouldn’t start back up. The motor appears to be dead, cold to the touch, no vibrations. It worked fine until unplugged & pulled to be cleaned.

When I purchased this system, the seller who either worked in or owned a pet shop said he’d recently replaced the impellers & both were in tip top working condition. One failed to start up the very day we brought it home. Again, a dead motor. The seller became very angry when I asked what the problem could be. I was hoping for a simple explanation, but he thought I was calling him a swindler even though I was ever so polite. I bought a new motor & all was well. Right now I’m not sure if the well under a year old motor went out or if it’s the other, but this sure is weird.
 
Check the impellor and shaft.
Try running the motor for a few seconds while it is disconnected to the filter.
Give the filter case a gentle rock to make sure there is no air trapped around the impellor.
Send the motor back under warranty :)
 
After stopping working my FX5 motor just needed a good cleaning and it continued working for appx. 5 years. I hope the same is for your FX4. Cleaning in the area inside the impeller.
 
I hope so too! Did the motor appear dead, as in cold & no vibrations? I will pull it again today & follow your suggestions. Thank you.

I see the motor is out of stock at Amazon & everyone else wants a lot more $$ & some ask a $30 shipping fee. At least Amazon is free shipping. Today, I need to figure out if the bad motor was the one purchased on 7/22 or the other.

At any rate each filter can handle 250 gallons & they are beneath a 125 lightly stocked severum tank, so I have time to play with solutions offered by you & Colin. Not seeing much online.
 
Yes, dead, neither sound nor movement. Someone told me to try and clean it and tap it on the side a few times if it didn't start. But basically maybe just the movement inside at the impeller area of cleaning it with an ear swab a few times did something - don't think I even tapped it, it just ran.

After that I was worried my luck would run out and happened to find an additional FX-5 used and bought it as a back up. One of them was making weird noises so I just swapped out the cannister for the other (leaving the BB baskets for the quiet one).

The spare FX-5 had been removed from it's tank and decommissioned when I moved before that. I actually haven't ever tried to clean the noisy one yet, but was looking into a back up motor.

The cost from Hagan was reasonable too.

I sure hope it works. That's expensive to replace. But as you mentioned you have adequate filtration.
 
Thanks, I sure hope so too! I haven’t had time to pull the FX4. Amazon does not have the motor in stock now; that’s where I got the first one I replaced, so I am waiting for new inventory.

But! Will the BB in the baskets fine when the filter is sitting there not in use?
 
If the media is kept wet and oxygenated (eg the filter is left running) then BB will live a few weeks with negligible die off. If its just kept wet (eg. the filter is left filled but turned off) a few days. If it dries out a few hours.

If you cant leave the filter running, then taking the lid of the canister so the water has some access to O2 might help. Or remove the media and put it in a bucket with an airstone would be better. Or better still remove the media filled baskets, and put them in one of your tanks somewhere that has good water flow. It will be oxygenated and fed ammonia in there.
 
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I kept mine going for months. I pulled off a hose from the top / removed it as it is supposed to be for cleaning (don't want anyone in the future readings to take that literally), and put the air bubbler down inside. Then would top off with dirty pwc water, periodically dump out around half of the water and refill with the dirty pwc water. Eventually I needed the air pump and let it go. Though I still have a 5G bucket of stones from my decommissioned Congos Lazy River tank bubbling away in the corner for over a year and a half (I should take that down, lol)
 
We just tried to follow Atkin’s advice to remove the trays and put them in another tank. I was going to use the goldfish 125 G tank & place it next to a large sponge filter connected, of course, to the air pump.

But the husband is unable to disconnect the hoses to pull the pump. puzzling, as he’s very mechanically inclined & has done it before.

Let me see if I understand your method. One way or another, I add a bubbler to the filter and occasionally replace water there with pcw? Unfamiliar with term pcw. Assuming it means dirty tank water.
 
Pwc - partial water change

I put the air tube with airstone into the whole canister. The air hose with back flow preventer valve, is connected to an air pump which of course is safely away from falling into water. Canister sits in a dry bath tub, or a plastic tote to minimize water splash on floor (optional).

Used pwc water the dirty water to feed the BB.
 
The trays and media remained in the filter.

But adding media back to the tank makes it useful too, so that might be better in the long run keeping maximum BB since it's working in the tank.
 
You can use the leg of a cheap nylon stocking knotted to hold the media and hang in back of the tank too. Just use a new cheap one and rinse well before using. It would mean not having to fit trays in the tank.
 
Thanks for the tips, Autumnsky! We were able to remove the canister lid without disconnecting any of the hoses. The entire basket is in the goldfish tank in front of a big sponge filter hooked up to a pump & near a Tidal 110 that puts out lots of bubbles. There are 2 AC filters further down. This is my understanding of what Aiken suggested. Does your method have any advantages? I'm rewarding the fish who poop directly into the basket extra pellets. They are fast learners!


This is really getting annoying how when i send a pic from the ipad to the laptop for resizing, it randomly rotates.
 

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Yes it's annoying.

FAST learners!!! So funny.

Not anything better, just BB grow more based upon their food source. So a running tank with fish will be fine.
 
Well, these BB should be feasting like Royalty in this tank.

I still don’t get why two FX4 filters that were working fine stopped when unplugged and pulled from under the tank, both with dead motors. I sure hope that doesn’t happen to the Electric Vehicle we have on order.
 
I still don’t get why two FX4 filters that were working fine stopped when unplugged and pulled from under the tank, both with dead motors. I sure hope that doesn’t happen to the Electric Vehicle we have on order.

Send them back to the manufacturer and get it replaced under warranty.

They might have had a bad batch of motors and are simply hoping not to do a product recall. Or it could be a crap design (engineering flaw). But if the motor is stuffed, just send it back. If enough people complain, they will do something about it.

This might be why the guy was getting rid of them.
 
I purchased one 7/22 and am uncertain if that’s the one that died, or the other, which would be ~3 yrs old. I will def find out. The guy sold me a complete setup at a good price: 125 G tank, stand, lid, lights, the two canister filters, a heater and 97 pds of Japanese lava rock. He said it retails at $6 a pound but he got it wholesale at $3/pd. I checked online & saw it going for $7/pd. That’s when I weighed it. It’s an attractive rock, but I’ve yet to use much of it.
 
It lives! The FX4 has mysteriously sprung back to life! The propeller went round & round when the motor was detached. Then it stopped. Then it started. The impeller was clean. I stuck a few Q-Tips inside where it sits & saw a few tiny specks of gunk. So it continued to start & stop. The husband tested his theory the cord had a short & was going to replace it if so, but no apparent short.

I decided to return it to the tank during a happy phase. This was prompted because the goldfish did not to seem to like the filter basket. Whenever the water is changed, they form a tight pod at the end farthest from the siphon/refill pipes. They went into pod formation as soon as the basket was added. I thought they’d get over it soon enough, but they did not. They resumed normal activity as soon as the basket was removed.

The FX4 continues to run fine. Today I’m going to photograph the serial number plates from both FX4 filters and contact Fluval.
 
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