Rummynose Tetra Swim Bladder Issue?

Hi all,

I’ve recently stocked my aquarium with a dozen(12) rummy nose tetras in a community planted tank. This is the first time I’m keeping them and did all the research and hours upon hours of youtube videos to understand how to take care of them.

It has been about 30 hours since I got them, and I’m now down to 5, with another one of them likely going soon.

I got them from a local fish store which I trust and have bought from before, they take care of their fish well and I have never had any issues aside from one time that one of my betta’s came with/got ich.

I’ve seen with the ones that have passed that they all kept losing balance, only one of their side(arm) fins were flapping and constantly swimming on their side or upside down. Eventually they would land on a plant leaf or substrate and continued breathing until they eventually stopped and lost their colour. Most had bloated/big bellies, with 2 of them that have passed having normal sized bellies. Which I suspect with the online readings is a swim bladder issue.

I acclimated all the fish for roughly an hour an a half, first by floating the bag for 20 mins then slowly adding water bottlecap by bottlecap into their bag.

All the other fish in the tank, which I got on the same day, 2 Black Mollies and 4 Julii Corydoras seem fine, swimming happily and exploring and eating fine. Also to point out that none of the rummy nose tetra have eaten since I got them. Have tried micro pellets, flakes, live baby brine shrimp and live moina (water fleas/kutu air), they dont seem to be interested at all. The food all end up either sinking to the bottom where the corys eat them or stay floating where the mollies eat them.

So I have no clue what’s going on and can’t find much answers to this issue. All of them have their red noses when the balance loss thing happened. I’ve attached some pictures of the fish that is currently experiencing this. The fish circled in yellow is the same fish in all the pictures.

Current tank setup as below, I am using test strips so there are ranges in some of the chemical readings.

10.2 gallon tank (60cmx28cmx23cm), have been cycled for over 2 months with fancy guppies previously stocked.
Water changes previously once a week, 30%
Ammonia: 0
NO2: 0
NO3: Between 10-25
CL2: 0
TCL: 0
GH: Between 25-50
KH: Between 0-40
pH: Between 6.4-6.8
Temperature: 26 Degrees Celcius

Using API Ammonia test kit & Yee 7-in-1 Aquarium test strips to test the water.

If anyone has any idea what is wrong with them do let me know, kinda tired of burying a fish in my garden every hour.

Thanks!

First, "swim bladder" disease is almost never that, but fish having difficulty swimming is one symptom of several problems, from water to genetic to internal protozoan.

Water. The parameters look OK, I assume the GH and KH are in ppm not dH. Good for soft water fish but a death knell to mollies so that is not going to work long-term. The other water issue is conditions, ammonia, nitrite, nitrate and any toxic substances. Why is nitrate so high? A range of 10-25 is a problem, if this is ppm. Do you have nitrate in the source (tap) water? Or is it occurring solely from the biological system? If it will be at 10ppm, it should never be allowed to increase like it seems to be doing. More water changes (greater volume), more cleaning of the substrate and filter, and not overstocking.

Which brings me to the stock...rummynose need more length to swim, so they are not a good choice in this sized tank. Mollies will not do well in soft water, but even aside from this they need a much larger tank, they will (if healthy) attain 4-5 inches.

Do you know the substance that the gravel and rock is made of?

There is always the possibility of bad fish, rummynose tetras are very sensitive and can easily be injured as well. But aside from this, the above water and tank size issues are critical here.

Byron said:

First, "swim bladder" disease is almost never that, but fish having difficulty swimming is one symptom of several problems, from water to genetic to internal protozoan.

Water. The parameters look OK, I assume the GH and KH are in ppm not dH. Good for soft water fish but a death knell to mollies so that is not going to work long-term. The other water issue is conditions, ammonia, nitrite, nitrate and any toxic substances. Why is nitrate so high? A range of 10-25 is a problem, if this is ppm. Do you have nitrate in the source (tap) water? Or is it occurring solely from the biological system? If it will be at 10ppm, it should never be allowed to increase like it seems to be doing. More water changes (greater volume), more cleaning of the substrate and filter, and not overstocking.

Which brings me to the stock...rummynose need more length to swim, so they are not a good choice in this sized tank. Mollies will not do well in soft water, but even aside from this they need a much larger tank, they will (if healthy) attain 4-5 inches.

Do you know the substance that the gravel and rock is made of?

There is always the possibility of bad fish, rummynose tetras are very sensitive and can easily be injured as well. But aside from this, the above water and tank size issues are critical here.

Click to expand...

I do believe that the GH and KH are in ppm, the sticker on the test strip bottle does not state it. The link to the test strip I am using is as below:

The high nitrate is probably due to the fact that I heavily overstocked that tank. Had like 15 fancy/mixed guppies, 6 otos and 3 hillstream loaches previously quarantining in there. All have been transferred to my main community tank, which is 3.5ftx2ftx1ft. Which is where I would’ve transferred all these fish after they finished quarantining. All lived with no issues whatsoever except some fin tears on some of the guppies.

I generally only do big water changes, like 50-70%, when the test strip read the nitrate between 25-50, also with the strip saying to water change when it passes the 50 mark. The nitrate fluctuates usually between 0-10 and 10-25 usually, but I don’t believe that is the issue, lot of stem plants feeding from the water column using them up.

I have a Dophin H200 HOB filter with biorings and use a lot of lava rocks for my hardscape as you can see in the pictures. So the ammonia and nitrites break down into nitrate quite fast in my past experience.

As for the substrate it’s fluval stratum plant and shrimp, probably about 8 months old at this point I think. There’s around 4kg in that tank. The gravel/small rocks, I have no clue what they are tbh.

But thank you though for the advice on the mollies, the source water where I am is a bit acidic, out of the tap it already registers between 6.4-6.8. I’ll get another tank for them and some PH Up.

TalonLock said:

I generally only do big water changes, like 50-70%, when the test strip read the nitrate between 25-50, also with the strip saying to water change when it passes the 50 mark. The nitrate fluctuates usually between 0-10 and 10-25 usually, but I don’t believe that is the issue, lot of stem plants feeding from the water column using them up.

Click to expand...

Stem plants like most all species of aquarium plants do not use nitrate unless ammonia/ammonium is totally exhausted. Livee plants help minimize nitrate by using more ammonia/ammonium than the bacteria can, and with plants using ammonia/ammonium there is no [or very minimal, undetectable] nitrite and thus no nitrate. The stocking is much of the issue here. You want to be encouraging the plants, not nitrifying bacteria. Nitrates should never be higher than in the 0 to 5 ppm range in a balanced biologically stable aquarium [unless they enter via the source water, which does not seem to be the case here].

TalonLock said:

But thank you though for the advice on the mollies, the source water where I am is a bit acidic, out of the tap it already registers between 6.4-6.8. I’ll get another tank for them and some PH Up.

Click to expand...

No, this is not the solution and it will make them even worse. Never use chemicals to mess with parameters, they don't work because there is more to this. The GH, KH and pH are connected. The issue here is the soft water, not the pH being acidic as a result. You need to harden the water naturally, which will in turn increase the pH and KH. This is involved, I am just mentioning the method. But this is not advisable in tanks with soft water fish like rummys, because they need it as soft and acidic as you can provide, naturally.

Water changes should be regular and consistent. Change the same volume once every week. Nitrates are not a guide; once the nitrates increase, the damage is already occurring. Water changes are intended to provide stability to prevent nitrates, not some cure once it is done. More in my article here:

Byron said:

Stem plants like most all species of aquarium plants do not use nitrate unless ammonia/ammonium is totally exhausted. Livee plants help minimize nitrate by using more ammonia/ammonium than the bacteria can, and with plants using ammonia/ammonium there is no [or very minimal, undetectable] nitrite and thus no nitrate. The stocking is much of the issue here. You want to be encouraging the plants, not nitrifying bacteria. Nitrates should never be higher than in the 0 to 5 ppm range in a balanced biologically stable aquarium [unless they enter via the source water, which does not seem to be the case here].



No, this is not the solution and it will make them even worse. Never use chemicals to mess with parameters, they don't work because there is more to this. The GH, KH and pH are connected. The issue here is the soft water, not the pH being acidic as a result. You need to harden the water naturally, which will in turn increase the pH and KH. This is involved, I am just mentioning the method. But this is not advisable in tanks with soft water fish like rummys, because they need it as soft and acidic as you can provide, naturally.

Water changes should be regular and consistent. Change the same volume once every week. Nitrates are not a guide; once the nitrates increase, the damage is already occurring. Water changes are intended to provide stability to prevent nitrates, not some cure once it is done. More in my article here:

Regular Partial Water Changes

Byron Hosking November, 2010 (rev April 2021) Nothing is more important when it comes to aquarium maintenance than regular partial water changes. The adage “an ounce of prevention is worth a pound of cure” certainly applies here. One frequently reads of products that will reduce the need for...

www.fishforums.net

Click to expand...

Ah I see. Thank you for the article. Was not aware quite a few of those points mentioned there on nitrates. Because all the videos I’ve watched on youtube from experienced fish keepers keep saying even up to 40ppm of nitrate is fine for a planted tank. So I should change my weekly water changes to 50% per week then to reduce it futher?

But now there’s a lot less fish than I had in there previously, so not sure how much water I should be replacing here.

I just did a 50% water change, the nitrates are measuring between 0-10 now.

Also just lost another rummy nose, down to 4 now. The mollies and corys still seem fine and active though, same as before. So I don’t think the nitrate levels were the issue.

As for making the water harder naturally for the mollies in another tank, how would I do that? Would limestone hardscape do the trick? Because they still seem fine now but I don’t want to jeopardise their health long term.

I agree, high nitrates were likely not the immediate issue. But nitrate at any level does impact fish, and it is best to think of it as a slow weakening of the fish, allowing other issues to be more problematic as the fish can no longer deal with these. It could have been bad stock, or something else we are not seeing.

The mollies are having to work very hard to "live" because the minerals they need to function properly are not in the water, primarily calcium and magnesium. In a tank only for such hard water fish you can use a calcareous sand/fine gravel substrate, calcareous rock, or use a commercial preparation. These are not the same at all like the pH adjusting toxic chemicals. Mineral salt supplements meant for rift lake cichlids can work here. Problem is, you have to prepare the water for water changes outside the tank so the parameters in the tank remain constant. It is doable but perhaps something you might like to postpone for the present, and concentrate on the immediate issue of dying fish. I did the hardening water years ago; noting is as easy on the aquarist as being able to use your tap water "as is" for water changes, and provided the parameters (GH, pH and temperature) are reasonably the same between tank and tap water, there is no harm ever in more water being changed. Keeping nitrates at 0 to 5 ppm is not difficult with proper stocking and maintenance.

The advice that nitrates up to 40 are not dangerous flies in the face of known science. Ammonia, nitrite and nitrate are all toxic to fish; the first two are much quicker to act, but the latter is still toxic too.

I would say the fish are dying from shock and stress. They probably just came into the shop a few days before you got them. They have been put in a tank with completely different water chemistry (pH, GH & KH). There's lots of light and no floating plants, and the fish can't cope with it. We used to see it all the time in the shop.

Turn the tank lights off for a week.

Put a picture on the back and 2 sides of the tank. You can use anything from aquarium backings, to coloured card, or even black plastic bin liners. Just tape it to the outside of the tank.

Try not to go near the tank for a few days and when you do approach it, go slowly.

Don't do any water changes for 2 weeks, then do small 10-20% water changes 2 times a week. Gradually increase it over a month.

Maybe contact the shop and find out when the fish came in and when they did/ do water changes.

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In a week's time when you start turning the tank light on again, do the following.

TURNING LIGHTS ON AND OFF
Stress from tank lights coming on when the room is dark can be an issue. Fish don't have eyelids and don't tolerate going from complete dark to bright light (or vice versa) instantly.

In the morning open the curtains or turn the room light on at least 30 minutes (or more) before turning the tank light on. This will reduce the stress on the fish and they won't go from a dark tank to a bright tank instantly.

At night turn the room light on and then turn the tank light off. Wait at least 30 minutes (or more) before turning the room light out. This allows the fish to settle down for the night instead of going from a brightly lit tank to complete darkness instantly.

Try to have the lights on at the same time each day. Use a timer if possible.