Filter Intake Killng Fish

[Curious1]

I have tried two different HOB filters and two different canister filters and I have lost one fish to each of them. They were sucked up against the intake of the filter. They weren't sucked in because they were too big to fit through the strainer but the suction apparently pulled them to the strainer and killed them. Any ideas how I might prevent this? Thanks

 

[mfdrookie516]

dead fish will almost always get stuck on the filter... unless you had a horribly powerful filter with some super tiny fish, i seriously doubt a healthy fish was sucked on to the filter

 

[Curious1]

dead fish will almost always get stuck on the filter... unless you had a horribly powerful filter with some super tiny fish, i seriously doubt a healthy fish was sucked on to the filter

Good point. I didn't think of that. I just bought the fish last night that I found on the filter this morning. Oh well.

 

[Jaybird]

you could try covering the filter intake with foam. I would have to agree with mfdrookie516: a healthy fish will not likely be too bothered by the filter intake.

 

[glassbird]

A fish does not have to be sick or dead to get stuck on a filter intake! Small fish, or clutzy fish with long fins can get trapped, too! And being stuck just for a few seconds can be enough to tear a long fin. Fancy goldfish have this problem, big time.

I cannot find foam filter material in my area easily, so I get creative with plastic mesh, the stuff crafters use. It comes in colors, but I mostly use black and dark green. I recently made a cylinder, with a round piece at the top and bottom, cut to fit my filter pipe at one end. I used nylon fishing line to tie fake plants to it, and it "disappeared" visually. Zero chance now of a fish getting too close, but the filter can still work with no loss of suction.

I also use the mesh to make filter boxes for my outdoor ponds.

 

[Curious1]

A fish does not have to be sick or dead to get stuck on a filter intake! Small fish, or clutzy fish with long fins can get trapped, too! And being stuck just for a few seconds can be enough to tear a long fin. Fancy goldfish have this problem, big time.

I cannot find foam filter material in my area easily, so I get creative with plastic mesh, the stuff crafters use. It comes in colors, but I mostly use black and dark green. I recently made a cylinder, with a round piece at the top and bottom, cut to fit my filter pipe at one end. I used nylon fishing line to tie fake plants to it, and it "disappeared" visually. Zero chance now of a fish getting too close, but the filter can still work with no loss of suction.

I also use the mesh to make filter boxes for my outdoor ponds.

You may be right. I found another fish dead on the filter when I got home last night. You'd think the strainer would be better tested before it went to market. The two fish that died appeared to be perfectly healthy.

 

[meegosh]

I agree with mfd... no healthy fish would get stuck to a filter intake. I have seen some small guppy fry get sucked into my filter and still have enough strength to swim out of it before getting sucked up the intake. If a small (less than half inch) guppy can swim out of it, anything should be able too.

 

[cabezon]

you said you just bought the fish. is this an established, cycled tank? how many fish did you add at once?

 

[WhiteDevil]

Use aqua clear filter sponges, they are sold everywhere.

I never leave my intakes unprotected due to this reason and weak/sick or just weak fish will get stuck to them constantly.

 

[Jaybird]

I have two coralife powerheads in my tank, each pushing just over 1000 gallons per hour, and when hair algae gets caught on the front screen of them my tangs swim right into that current to nibble the caught algae. I also have small snails and shrimp crawl right across the intake screens for them.....zero casualties. There is no hang-on-back filter that is going suck-in or push-out that kind of flow and if fish and inverts have no problem with over a 1000 gallon per hour flow, they won't be getting stuck to your intake....if they are health in the first place.

A lot of fancy goldfish can't even swim. They just kind of wobble forward because of ages of inbreeding to develop the fins, weird eyes, etc.

Sometimes the fish you get from the LFS are new stock, or wild-caught. They are not always hardy or used to aquarium conditions. Neon tetras are a great example of this. You always need to buy twenty when you only really want fifteen because you can always expect some not to make it.

As well, I would be interested in knowing what kind of fish these are, how old the tank is, and what the water parameters are. That could also help. It may be a water issue and the fish are becoming sick, or weakened, because of it.

 

[Curious1]

I will go out and get an Aqua Clear filter sponge tonight! Thanks for that info. These are definitely NOT sick, fish. I thought the first two that died might have been but after the last two died I know it is the filter. These were robust healthy fish that have been in the tank for a month. I just put the new filter on in the past four days. It has killed one fish per day since putting it on the tank. Why in the world would a company design something that would allow fish to be sucked in? I know I can’t be the only one who has experienced this. Why isn’t that sponge just part of the strainer instead of a separate option? The casualties are a glofish, hatchetfish, cardinal tetra, and oto catfish all of which were doing fine until this new filter was installed. If they are sick for some reason it is very coincidental they died when the new filter was installed. I tested the water and everything is within normal levels.

 

[Jaybird]

Did you remove the old filter when you installed the new one?

With freshwater tanks, almost all of the nitrifying bacteria can be found in your filter media. If you changed filters then you have likely removed almost all of your bacteria that converts ammonia to nitrite, and nitrite to nitrate. In essence, your tank will need to cycle again.

 

[Curious1]

Did you remove the old filter when you installed the new one?

With freshwater tanks, almost all of the nitrifying bacteria can be found in your filter media. If you changed filters then you have likely removed almost all of your bacteria that converts ammonia to nitrite, and nitrite to nitrate. In essence, your tank will need to cycle again.

No. I had a internal filter working with the media for bacteria in it and I left that running. I also put in a bacteria seed to help the tank which I purchased at the fish store. The test I ran on the water indicated all levels were fine. The fish don't appear stressed.

 

[Markstanfill]

My SAEs like to hang on the intake of my Koralia powerhead. They love it and can get off at any time they wish. Pushes 240gph.

 

[mfdrookie516]

i have a yellow lab that sleeps stuck to the side of my fluval 405... its way way way stronger than any hob filter and never had any problems... seriously, if the filter had issues sucking up fish, they would have recalled it long ago... aquaclear filters are one of the best, if not the best, hob filters you can get... there is just no way it is 'killing' healthy fish

 

[Curious1]

i have a yellow lab that sleeps stuck to the side of my fluval 405... its way way way stronger than any hob filter and never had any problems... seriously, if the filter had issues sucking up fish, they would have recalled it long ago... aquaclear filters are one of the best, if not the best, hob filters you can get... there is just no way it is 'killing' healthy fish

Any ideas then what would be killing them if all the water tests are coming back normal and I see no bullying going on in the tank?

 

[WhiteDevil]

internal parasites and diseases, just plain bad fish can happen.

 

[Curious1]

internal parasites and diseases, just plain bad fish can happen.

You may be right but each of the four dead fish came from different stores. This morning I noticed white spots on the Mollie's tail. I suppose that is some awful disease too. I feel like I should have never invested in an aquarium. They appear to be a huge source of stress and expense. I'll probably get a lot of replies saying how easy it is and I'm doing something wrong and that may be the case but I've followed every instruction in the book about cycling the tank not over stocking it, not over feeding etc. Anyone interested in a slightly used 29 gallon tank?

 

[Jaybird]

What water test kit are you using? How old is it?

You said that you installed a new HOB filter and then....poof....fish started dying by getting stuck on the filter intake. Hatchetfish are a top-water species and the catfish is a bottom-water species. It's not likely that the hatchetfish was wandering around the bottom of the tank to get sucked into an intake.

What internal filter media are you talking about. In your original post you said that you tried two different HOB and two different canister filters. Each time you switch filters you lose your beneficial bacteria....unless you keep ALL of your original media. If you swap one canister filter for another but only put in half of the ceramic tubes (or bio balls) then your tank will have a mini cycle. That short cycle can be enough to kill fish.

Don't waste your money on those bottles of bacterial culture from fish stores. They are kept on shelves, so there will be minimal, if any, useful bacteria in there by the time you buy it.

Check your ammonia, nitrites, and nitrates. Let us know what those are. Is the tank heavily planted, or just rocks? What size is the tank and how many fish do you have in it? How long has the tank been running for? When was the last time that you added new fish?

The issue is likely water conditions, but it could also be disease or parasites. It's not likely to be a problem with filter flow. I have a pump that is rated for about 1100GPH, but at the current head height is probably only pushing out about 700GPH. I have two Koralia powerheads rated at 1200GPH with one maxijet (rated at 295GPH) on a wavemaker.

 

[Curious1]

Thanks so much for taking your time to try to help me. You are correct the hatchetfish are surface dwellers but I did see them swimming several time mid level. To give you some background the first filter I had was a Marineland HOB which came with the tank. It didn't seem to keep the tank clean and it made a noise that kept me awake. At the advice of someone on the forum I bought a Fluval internal filter. That one is great and is silent. It has chambers in it for several different types of media one being biological. Forgive my simplicity on the subject but I'm really a novice. I have kept that one in the tank and never turned it off because it has not given me any problems. However, I didn't feel it would be enough to adequately filter my tank so I wanted something else. I then purchased a Marineland canister filter. The first two nights I came home from work it had lost its prime and wasn't working. I couldn't have something that unreliable especially since I'm going to be leaving on vacation so I took it back. The store said I must have had a defective one and swapped it out for an Eheim canister. This one was not a self priming one. When I got home with that one I followed every instruction I was given I the store to prime it and it wouldn't prime. I then followed the instructions exactly as they were in the manual and it still wouldn't prime. Then I called a neighbor over with an aquarium to see if they could get it primed. They couldn't either so I took that one back. Then they tried to sell me a wet/dry filter. I declined that saying I had been through enough already and just wanted something very simple which would be efficient and quiet so I went with the Aqua Clear HOB. It has been quiet and appears to be keeping the water clean and it also has the media for the good bacteria.
The key here is I never took the internal filter out so it should have retained the beneficial bacteria. In addition to that I seeded the tank with beneficial bacteria which I bought from the fish store. I didn't know the bottles of bacteria were a waste of money, thanks for that info. The one I bought was refrigerated if that makes a difference. I did also buy some "bio balls" from the fish stores tank which is supposed to transfer good bacteria from their tank to mine.
I checked the levels this morning and nitrate was a bit high as it was last night. I put something in last night that is suppose to reduce nitrates but nothing has happened yet. I do have several live plants in the tank. The tank is 29 gallons and I have five cardinal tetras, two balloon mollies, two regular mollies, one oto catfish, two Cory catfish, and two dwarf African frogs. I noticed this morning one of the mollies has white spots on its tail so I assume the tank is now infected with ich. The tank has been set up for a month. The last time I added new fish was last weekend a few of the tetras. I also have a UV filter which has been turned off after adding the beneficial bacteria at the request of the fish store owner.