having problems with a FX4 filter

FishHobby99 said:

I am also having a terrible time with my Fluval Aquaclears. I have several 70s and 110s. The media, especially the sponge, floats up so that the bio cylinders are out of the water. This is a common problem. I see many posts on Redditt etc. Some remove 1 of the 3 inserts. Some try weighting down the baskets with pebbles. I did this & they still float. I am about to replace their bricks of white foam with the type of black foam I use in my sump filter.

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The most common reason AquaClear sponges float is due to air getting into them. This normally happens when you clean the filter and get it going again. They suck air in with the water while self priming. Once there is no more air in the intake tube, and there is just water flowing through the filter, then there shouldn't be any more bubbles getting into the sponges or other filter media.

If you leave the filter media (sponges, ceramic beads) in a bucket of tank water while the filter gets going and wait until all the air is out of the intake tube, then push the sponge into the filter and squeeze the air out, it should stay down. Careful doing this because you can slosh water onto the floor.

The other reason the sponges float is if they are really dirty. The filter is pumping the same amount of water through the filter but it can't go through the actual sponge because of the gunk build up in the sponge. Cleaning the sponge in a bucket of tank water usually fixes this issue.

FishHobby99 said:

By disassembling the motor do you mean removing the impeller? That will have to be done tomorrow when the new one arrives.

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Disassembling the motor means removing the plastic bit that holds the impellor/ impeller in place and removing the impellor assembly. (I'm staying with impellor coz it's easier to write). The impellor assembly should have the impellor, impellor shaft (steel or ceramic), rubber grommets on either end of the impellor shaft, and maybe small plastic washers that go between the rubber grommets and the impellor.

Some impellors have the plastic washers and some don't. You should check the other filter that works and maybe do a Google search or go to the manufacturer's website and see if they have a diagram of the impellor assembly for that filter. See if it is meant to have plastic washers.

Basically, take it out, clean it and make sure everything is where it should be, then set it back up.

There is a possibility you have the wrong impellor in the filter. You need to see if both are the same size and have the same number of plastic blades. A number of filters have similar sized impellors and sometimes the wrong impellor is put in a bag and given an incorrect label. Comparing the 2 impellors side by side should rule that out.

I've just looked at the manual. I think the reason the previous owner said to replace the impeller yearly is because that's what the manual says in the "maintenance frequency chart".

This is taken from the Fluval FX4 manual

Fishmanic said:

@FranciscoB
You’ve been holding out on us by not entering those tanks in our Tank of the Month contests. Our August contest will feature tanks sized at 31 gallons and larger. You should enter one of your tanks in the contest.

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Many thanks. I am still new to this forum, but have had fish and aquaria for >5 decades.
I might submit sometime. I have seen other contests where I could not enter (bettas, nano tanks, up to [small size]). My smaller tanks are 40g. Cheers!

@FranciscoB
later in the year, we will have a FOTM contest for any fish...especially "oddballs." Hope you enter one of your fish in the contest.
If you have a pet besides fish, our Pet of the Month resumes tomorrow.

Colin_T said:

Disassembling the motor means removing the plastic bit that holds the impellor/ impeller in place and removing the impellor assembly. (I'm staying with impellor coz it's easier to write). The impellor assembly should have the impellor, impellor shaft (steel or ceramic), rubber grommets on either end of the impellor shaft, and maybe small plastic washers that go between the rubber grommets and the impellor.

Some impellors have the plastic washers and some don't. You should check the other filter that works and maybe do a Google search or go to the manufacturer's website and see if they have a diagram of the impellor assembly for that filter. See if it is meant to have plastic washers.

Basically, take it out, clean it and make sure everything is where it should be, then set it back up.

There is a possibility you have the wrong impellor in the filter. You need to see if both are the same size and have the same number of plastic blades. A number of filters have similar sized impellors and sometimes the wrong impellor is put in a bag and given an incorrect label. Comparing the 2 impellors side by side should rule that out.

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The impellers look the same. The new one arrived today. Same thing. A few jerky spasms felt when touching the motor. No water circulation. The new motor will arrive tomorrow. If that fails, guess I’ll have to regroup & reread this post & the one below carefully & take a look at the Fluval manual.
thanks.

If everything is fitted in it properly and the motor starts for a few seconds and stops it is probably dodge/ faulty.

Sounds similar to a problem I had with a brand new FX6 (see this thread). Significant juddering from the hoses like the pump was turning off and on and low and inconsistent flow. At one point it cut out entirely and needed to be turned off and on.

I'd tried disassembling the impeller etc and that didn't help. Did it again and no good. Then the next day it just started working properly. Six months on and not had a single problem.

I'd contacted the online store in Germany I'd bought it from and they said they'd send a replacement as soon as one was in stock but I had to send the faulty one back first, which was problematic as the tank was up and running. As I say, it fixed itself (or somehow by repeatedly removing and replacing the impeller/motor I fixed it). I'm not sure if the motor was ever so slightly loose and just needed tightening to the housing slightly.

Colin_T said:

If everything is fitted in it properly and the motor starts for a few seconds and stops it is probably dodge/ faulty.

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You mean the new motor would be faulty? Or something else? I wound up ordering it from Amazon. Got 10% off due to Prime Day. We pay for Prime. Many items delivered the next day as an Amazon Warehouse was recently built here. Nice thing about Amazon is all items can be returned at their expense. They say free shipping. LOL. Membership fee goes up every year. Alas, they’re now saying the motor will arrive tomorrow, not today. Sigh.

The other fx4 continues to hum along & circulate water. So strange the previous owner says they were both working like champs until he took the system down the morning I picked it up. Still think I got my money‘s worth at $500. Has two 300 W Fluval heaters, nice air pump & stones, nice hood with LEDs, & buckets of pool sand. I‘ve been using Playground sand & truly don’t know the difference. But I want both fx4s working! Oh, and very heavy buckets of some rocks he says that sell for $6 a pound. I think he said they were Japanese volcano rocks, but can’t exactly recall. Quite beautiful.

I hated the look of the stand. I closed off the open shelves in the center and painted the whole thing black. Much nicer. Will take a pic for you now. Thanks so much for all your help on this issue!

FishHobby99 said:

You mean the new motor would be faulty? Or something else?

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The motor you are having problems with could be faulty.

Colin_T said:

The motor you are having problems with could be faulty.

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That‘s our current thinking.

I’m having problems uploading photos and am trying again. One is of how the tank looked originally with open shelving between two doors that conceal the big filters.The other is how it is now, after I closed off the shelving with an oak panel & painted everything black. The tank is said to be high quality, but the stand is laminated particleboard. I’ve read numerous negative reviews about this stand. The previous owner says it’s structurally sound and the problems are caused by people not keeping the stands dry. The one I have looks brand new. Not a drop of water damage. The husband was prepared to reinforce the stand, but is holding off based upon the seller‘s comments. He did install four more 4x4 posts beneath the flooring, same as for the 110 G.

Nice work with the stand. Looks much nicer.
I have the exact same tank/stand (Aqueon), except my stand was all black. I consider the tank as good quality, but not the stand, although I am currently using it. I did place it on top of a well braced 2x4 frame, just so that it is off the ground, to reduce damage due to potential spills or accidental flood.
One suggestion for your FX4s is to place them on plastic pails, to contain likely occasional minor spills that happen during servicing, or due to (rarely) a valve not quite sat perfectly and thus having a small drip. Of course this would not contain a major leak.
Another is that in one of your earlier photos I noticed your electric power strip sitting right next to the filter. That could be dangerous (again, minor spills). Elevated is best.
Hope you can get both FX4s to work properly for you!

Great tips! Thanks, Francisco. I put one in a dishpan & will do the same for the working one later. Also moved the power strip to behind the tank, but it’s difficult to access, so thinking of buying one with a longer cord and mounting it on the wall next to the tank.

I believe the stand has a wooden frame and that only the doors and side panels are particleboard. One would think if properly laminated it wouldn’t be damaged by water, but that’s what I’m being told, water penetrates the particleboard. I don’t get it. What did they laminate it with? Paper mache ? Too bad we don’t think of your 2x4 braced frame. How high above the ground is it?

Colin_T said:

The most common reason AquaClear sponges float is due to air getting into them. This normally happens when you clean the filter and get it going again. They suck air in with the water while self priming. Once there is no more air in the intake tube, and there is just water flowing through the filter, then there shouldn't be any more bubbles getting into the sponges or other filter media.

If you leave the filter media (sponges, ceramic beads) in a bucket of tank water while the filter gets going and wait until all the air is out of the intake tube, then push the sponge into the filter and squeeze the air out, it should stay down. Careful doing this because you can slosh water onto the floor.

The other reason the sponges float is if they are really dirty. The filter is pumping the same amount of water through the filter but it can't go through the actual sponge because of the gunk build up in the sponge. Cleaning the sponge in a bucket of tank water usually fixes this issue.

Click to expand...

I have always struggled with how thoroughly to clean the sponges. I’m afraid of removing too much BB.