Molly with ripped fin, swimming sideways

[SophieLeigh]

Hi everyone,

I am pretty new to owning fish. I've had these fish for a little over three months now and this is the first time I'm noticing any problems. I have 2 black panda mollies, an albino bristlenose pleco, and a snail (I think it's a zebra nerite snail). A couple of days ago, I realized that one of my mollies had started swimming sideways at the bottom of the tank and swimming in circles. Upon looking closer last night, it occurred to me that the fin on his back is ripped. He seems to be trying very hard, but he's just lacking the balance to swim normally, and because of this, I'm not sure if he's been able to get the flakes that I feed them. The other fish (the other molly and the pleco) don't seem to bother him too much, they do nudge him every once in a while though as if they're trying to push him along.

So a couple questions: will his fin heal and will he ever be able to swim normally again?
How can I make sure he's getting food in the meantime if he's unable to get to the top of the tank?
I don't think the other fish are antagonising him, but should I separate him for a while anyways?

Thank you!

 

[SophieLeigh]

some additional info/corrections: they are actually gold panda mollies, it's a 10 gallon tank, and the ripped fin is almost entirely gone

 

[Jessie J.]

A picture would help to determine what it is.

 

[Colin_T]

Hi and welcome to the forum

How long has the tank been set up for?
How often do you do water changes and how much water do you change?
Do you gravel clean the substrate when you do a water change?

How often do you clean the filter and how do you clean it?

Have you checked the water quality for ammonia, nitrite, nitrate, pH and GH?
If yes, what are the results in numbers?

Can you post a picture of the sick fish?

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Fish spinning around or swimming in circles is normally a protozoan or bacterial infection in the brain. These occur in tanks that don't get enough water changes and cleaning, and mollies are much more prone to health issues when kept in soft water (water without many minerals in).

You can try doing a 75% water change and gravel clean the substrate each day for a week. Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

You can add rock salt (often sold as aquarium salt), sea salt or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

If you only have livebearers (guppies, platies, swordtails, mollies), goldfish or rainbowfish in the tank you can double that dose rate, so you would add 2 heaped tablespoons per 20 litres and if there is no improvement after 48 hours, then increase it so there is a total of 4 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria but the higher dose rate will affect some plants. The lower dose rate will not affect plants.

After you use salt and the fish have recovered, you do a 10% water change each day for a week. Then do a 20% water change each day for a week. Then you can do bigger water changes after that.

 

[SophieLeigh]

I bought my mollies about a week after setting up and preparing my tank, so about 3 months. Unfortunately it's very hard to get a picture of the sick fish because he's so little and moves around a lot.
I have a pleco and a snail, and I read that if you have algae eaters you can change the water less than if you do not. I have changed the water (about 75% each time) twice since getting the tank.
I bought supplies to test the water today, and I don't remember the exact numbers, but the pH and GH were pretty much perfect, and it was a little high in nitrates and nitrites, and much too high in ammonia.
My tank is supposed to alert me with a light when it's time to change the filter, and that feature apparently doesn't work, so it's been much too long since I've changed the filter, so I changed that, and I also did a 75% water change (as well as added a biological booster solution, as I always do when changing the water).
He's only had a ripped fin for a few days, and it was very sudden, so I don't know if it got torn by a tank decoration or another fish (I've been reading up on fin rot, and it doesn't match up with the symptoms of that. There is no red or anything around the ripped fin, there is only the injury.)

I do not have the time in my schedule to do a 75% water change daily until he heals, would a 10-20% be okay?

I'm hoping my sick fish (his name is Apollo) is just a result of the filter being too dirty to do its job and keep the tank clean, and that he will start to feel better soon now that it can work normally again.

 

[Byron]

Members will need to know exact test result numbers. For example, I have no idea what pH and Gh being "perfect" means. And when you say ammonia is "much too high," and nitrite and nitrates are "a little high," this sounds serious. But without the numbers we are basically guessing. Mollies however are highly susceptible to ammonia, not to mention nitrite. Nitrate depends upon the actual number.

Symptoms of poisoning by ammonia and/or nitrite will often include inability to swim, torn fins, and increased respiration. So this is certainly one possibility.

As for the filter, generally we suggest you keep the filter well cleaned, meaning, rinse it regularly, at every water change won't hurt. Replacing the media is not usually advisable or necessary. The main thing is that water is able to flow through the media without blockage, and the media is rinsed to keep it able to do the job.

 

[Colin_T]

I have a pleco and a snail, and I read that if you have algae eaters you can change the water less than if you do not. I have changed the water (about 75% each time) twice since getting the tank.

I bought supplies to test the water today, and I don't remember the exact numbers, but the pH and GH were pretty much perfect, and it was a little high in nitrates and nitrites, and much too high in ammonia.

Algae eating fishes and snails eat lots of plant matter and produce huge amounts of poop compared to other fishes. This means they need more water changes and gravel cleans than other types of fish.

Algae eating fishes should also have a piece of driftwood in the tank and you can leave the lights on a bit more to encourage algae. They will also eat raw or cooked cucumber, zucchini & pumpkin. Just make sure these are clean and free of chemicals.

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Any ammonia or nitrite readings above 0.0 will make fish sick and can damage their fins.
Any nitrate level above 20ppm will make fish sick. Try to keep the levels below this.
Mollies need a pH above 7.0 and a GH above 250ppm to keep them healthy.

My tank is supposed to alert me with a light when it's time to change the filter, and that feature apparently doesn't work, so it's been much too long since I've changed the filter, so I changed that, and I also did a 75% water change (as well as added a biological booster solution, as I always do when changing the water).

Filters should be cleaned at least once a month and preferably more often. Every 2 weeks is great if you can do that. Wash filter materials in a bucket of tank water. Wash filter cases and impellor assembly under tap water.

Filter materials should last for years. If you have cartridges that need replacing every month or so, then that is a marketing gimmick. Find some sponges from another brand of filter and put the sponges into your current filter along with the old filter cartridges. After a couple of months you can throw the cartridges away and stay with the sponges. The sponges will develop colonies of beneficial filter bacteria and can be squeezed out in a bucket of tank water and will last for years. You can also get cylindrical sponges with a hole through the centre and these can go over the intake strainer of the filter to add more filtration media.

I do not have the time in my schedule to do a 75% water change daily until he heals, would a 10-20% be okay?

The best way to heal a fish is to do big daily water changes, gravel clean the substrate and make sure the filter is clean. This cleans up the environment and makes it a healthier place for the fish to live and recover.

If you can do a 20% water change, you can drain out 75% at the same time. Big water changes are much better for the fish because they dilute nutrients and disease organisms more effectively than small water changes.
eg: If you change 20% of the water you only dilute the nutrients and disease organisms by 20%. This leaves 80% of them behind to continue affecting the fish.
If you change 75% of the water you get rid of 3/4s of the nutrients and disease organisms and only leave 25% of them behind.

If you have any ammonia or nitrite readings in the water, you need to do big water changes to dilute this asap.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.