Is My Filter Killing My Fish and Replacement Advice

[Gemtrox42]

I have a 29g tank with cardinals, a honey gourami, dwarf corys, cherry shrimp and a clown pleco. I use an Aqueon QuietFlow10 filter, and put a cylindrical sponge over the intake so it doesn't suck up shrimp or snails. For a half a year, this hasn't been giving me any issues until recently. Within the last month, I've found 3 fish stuck between the intake and the sponge (There is a small gap between them because I couldn't find a snugly fitting one). 1 was a honey gourami and two were cardinals. My water is great. All fish were showing no physical signs of disease or disability prior to their deaths, except for one cardinal who might have been swimming apart from the school beforehand but I can't be sure. I check my tank and count my fish daily, so all were found within 24 hours of death, and all had good coloration still (I think that means they were healthy/recently died?).

To me, this looks like my filter is killing my fish. The odds that 3 in a row would be sucked in after dying seems highly doubtful, but I wanted to get some insight before making a snap purchase. Am I missing another explanation, or are the odds of the fish dying and ending up there higher than I think?

Assuming my filter is the problem, I would also love some suggestions for replacement. I have a tank of slow water fish, so a low-flow filter would be my preference, but I know nothing about them. Thanks.

 

[xxBarneyxx]

Fish can sometimes get stuck. I have had it happen to me. However most of the time with something like this its that the fish was ill and incapable of swimming properly and then got sucked into the filter. All the water in the tank goes through it so a fish with issues swimming or already dead will almost always get to it eventually.

For your filter intake get some woman's tights. They can cover the intake without restricting flow or taking up space. Just make sure you clean/replace them regular so they don't get clogged up.

I would also check water parameters in case there is a bigger issue there.

 

[Essjay]

woman's tights.

Pantyhose

 

[Slaphppy7]

Save the pantyhose for your water changer siphon, use these instead: https://www.jungleaquashrimp.com/st...er-intake-guards-for-aquariums-shrimps-tanks/

 

[Gemtrox42]

Fish can sometimes get stuck. I have had it happen to me. However most of the time with something like this its that the fish was ill and incapable of swimming properly and then got sucked into the filter. All the water in the tank goes through it so a fish with issues swimming or already dead will almost always get to it eventually.

I see what you're saying about illness, and I agree, although like I said nothing appeared to be wrong. The second part I do personally disagree with though - I've lost easily over two dozen fish while using this filter, many unfortunately to an ich outbreak. These incidents are only the second third and fourth times I've found them in the filter intake. But maybe my experience is unusual and it's actually incredibly unlikely they didn't end up there.

For your filter intake get some woman's tights. They can cover the intake without restricting flow or taking up space. Just make sure you clean/replace them regular so they don't get clogged up.

I would also check water parameters in case there is a bigger issue there.

Alright that's an interesting idea, I'll look into it. My water parameters are fine, only thing is I've got almost no nitrates but I think that's just a sign of a robust biofilter right?

Also I'm assuming you don't think it needs to be replaced, but do you have any recommendations for low flow filters?

 

[Gemtrox42]

Save the pantyhose for your water changer siphon, use these instead: https://www.jungleaquashrimp.com/st...er-intake-guards-for-aquariums-shrimps-tanks/

Isn't the point of the water changer siphon partially to remove debris from your tank like decaying organics though?

Also, these look good but is there a gap at the top big enough for something to get caught in? Otherwise I'm sticking to my sponge

 

[Slaphppy7]

Isn't the point of the water changer siphon partially to remove debris from your tank like decaying organics though?

Also, these look good but is there a gap at the top big enough for something to get caught in? Otherwise I'm sticking to my sponge

Yes...I'm referring to regular WC's with no vacuuming.

There is no gap at the top of the mesh filters, they slide over the filter intake.

 

[xxBarneyxx]

Alright that's an interesting idea, I'll look into it. My water parameters are fine, only thing is I've got almost no nitrates but I think that's just a sign of a robust biofilter right?

Also I'm assuming you don't think it needs to be replaced, but do you have any recommendations for low flow filters?

No nitrates might be ok. If you have a lot of plants.

If you don't then no nitrates is a worry. I have tried a lot of methods for nitrate removal and it takes a LOT of specialist setup and even then is a bit hit and miss. A HOB filter is definitely not removing nitrates.

In terms of the flow rate being too high. From looking up you filter it looks like it's species for about 70lph.

In terms of comparison the smaller filter I have to hand at the moment runs at about 300lph and I have used that with most common tropical fish with no issues. The only time I would worry about needing low flow would be with long finned fish like Betta's. Cardinals will have no issues swimming against the pull of a 70lph pump.

 

[Gemtrox42]

No nitrates might be ok. If you have a lot of plants.

If you don't then no nitrates is a worry. I have tried a lot of methods for nitrate removal and it takes a LOT of specialist setup and even then is a bit hit and miss. A HOB filter is definitely not removing nitrates.

I have a few plants, I definitely wouldn't say a lot though. And I have some nitrates, just a very small amount. What about that isn't good?

In terms of the flow rate being too high. From looking up you filter it looks like it's species for about 70lph.

Oh, I know they can swim against the flow, but they don't like the waterfall it creates coming out, which they avoid and that means they don't use 1/4th the tank. I thought it would be nice to give them some room by removing the waterfall.

 

[xxBarneyxx]

I have a few plants, I definitely wouldn't say a lot though. And I have some nitrates, just a very small amount. What about that isn't good?

Oh, I know they can swim against the flow, but they don't like the waterfall it creates coming out, which they avoid and that means they don't use 1/4th the tank. I thought it would be nice to give them some room by removing the waterfall.

It's possible that nitrates are low because of water changes. That would be fine. Just your original post put it down to biofiltration which is pretty unlikely.

I don't tend to use HOB filters so that could be an issue with the down flow.

If you are looking for filter replacements I would always recommend pretty much any fluval or ehiem canister filter. I prefer canister filters for ease of maintenance and because I don't like a lot of equipment in my tanks. I have fluvial and ehiem kit that is 15+ years old and still going strong so while they tend to be on the more pricey side they are worth the money long term.

If you can afford it I would always recommend one with a built in heater. It's not a necessity at all but again it's one less but of kit in the tank and I have found that it gives a much more even water temp.

In the 68l I'm setting up I had an internal filter and 100w heater while I got some spare parts for the main filter. One side of the tank was 2C hotter than the other. This is in a 2ft tank. Once the canister filter with heater was on there both sides where within half a degree of each other.