Tropical Fish Keeping banner

I lost 2 rasboras already, what's going on

5K views 12 replies 4 participants last post by  Shewbert 
#1 ·
My 20 gallon long tank recently finished cycling and I added 6 harlequin rasboras, 6 albino cories, and 1 betta. When I got my rasboras, 2 of them were super fat and the rest looked normal. Within 2 days the first fat one died and I tested my water but everything was good.

Now it's been a little over a week and the 2nd fat one died. The water parameters are still good, so what is going on? Before my rasbora died, it was swimming away from the school and acting little strange. Do you think it was sick or that it had something to do with the rasboras' fatness?

My other rasboras, cories, and betta are still doing great but I'm worried that they're going to get sick. My water has 5ppm nitrate, a hardness of 180ppm and a ph of 8. Do you think there's something wrong with the water that I'm just not testing? What should I do about my dying fish?
 
#2 ·
More than possible they had bloat when you bought them,, you said they were superfat,,
really advise not to buy fish that is overly fat, some people think,,that fish is ok, it's nice and fat,,,no, same in as humans fat is unhealthy.
Ray
 
#3 ·
I'm not sure what kind of filter you're using......

But even after you cycle a tank, you have to be careful when you introduce new fish.

Not sure if you QT'ed your fish before adding them to the tank, but anything you buy from the petstore has a good chance of introducing unwanted pathogens into your water.

Also when adding new fish, it's NOT a good idea to add 13 fish @ the same time.

Depending on the type of fish & the additional bio-load, your filter might not be established enough to keep up with the EXTRA ammonia your new fish were creating.

Introduce a few fish every 10-14 days so your filter can grow enough bacteria to catch up.

The rasboras most likely died from a ammonia spike.
 
#4 ·
I have tested the ammonia every day and it's always been at 0. Also I aded the rasboras and waited a few days before adding the cories to make sure everything was ok.

Now my cories are acting weird too. They are sitting still at the bottom of their cage and they barely move. I noticed that they would go up to the top for air sometimes, so do you think that my fish are running out of air?
 
#5 ·
I have tested the ammonia every day and it's always been at 0. Also I aded the rasboras and waited a few days before adding the cories to make sure everything was ok.

Now my cories are acting weird too. They are sitting still at the bottom of their cage and they barely move. I noticed that they would go up to the top for air sometimes, so do you think that my fish are running out of air?
It is normal for corys to breathe air. Have a read of one of our cory profiles, it explain why. The albino cory is probably the albino variant of the species Corydoras aeneus, so click the shaded name for the profile.

However, this doesn't mean the corys are fine, though they may be. They might be adjusting to their new environment; corys do not like being moved and sometimes it can take several days. There is also the possibility that there is something in the tank. But this is not easy to ascertain sometimes. Don't add any more fish, observe the tank and fish, feed sparingly, do a water change every week of 1/2 the tank. Keep us posted.

Byron.
 
#6 ·
Should I take my betta out of the tank? I really don't want him to die since I've had him for months and I don't know what's going on in my tank. Also, should I continue to feed the fish even if they aren't doing well?
The rasboras seem to be swimming normally and my betta seems ok so it's just the cories that are really struggling. They were super active and hungry yesterday, so I'm surprised that they are doing so badly now.
 
#7 ·
Should I take my betta out of the tank? I really don't want him to die since I've had him for months and I don't know what's going on in my tank. Also, should I continue to feed the fish even if they aren't doing well?
The rasboras seem to be swimming normally and my betta seems ok so it's just the cories that are really struggling. They were super active and hungry yesterday, so I'm surprised that they are doing so badly now.
Without knowing exactly what a disease is, or if there is a disease, it is difficult to suggest moving fish, etc. I would tend to leave things alone. Water changes, even 2 a week now that I think about this again, can work wonders, half the tank volume each time, use a good conditioner. Feed daily but sparingly, esp if the fish are eating.
 
#8 ·
Thanks for all the advice. I will do a 50% WC tomorrow and see if that helps. The cories perked up all of a sudden and are swimming and sifting for food so I have hope that I won't loose any more fish.
 
#9 ·
My dad is on a training seminar at the moment so I will answer on his behalf.

catfish have a labyrinth organ that allows them to breath atmospheric oxygen. In fact, they must have access to oxygen from both the air and from the water (they also have gills) or they won't survive.
Although corydoras are bottom dwellers you will frequently see them come to the surface for a gulp of air. This is normal behaviour.

Corydoras like to congregate together in the aquarium. They usually hang out together while searching for food and they even rest together. You will often see one catfish resting his head on the body of another catfish. They don't even have to be the same species to get along and become friends. They only need to be of the genus Corydoras. Because of their social nature, you should not keep only one corydoras in your tank. You should always have at least two, and 3 or more is even better (as long as you have the room in your tank). Corydoras don't survive long alone. They can stay fairly inactive/resting for quite a long time, you might find out that they are being more active during the night, before you go to bed place a piece of zaccuri or cucumber in the tank, if it is well eaten in the morning, they will more than likely being night active.
If they are eating well, able to swim to the top to gulp, I wouldnt worry too much.
Hope this helps.
Mandy (Marine biologist/vet)
 
#10 ·
My corydoras seem to be doing well now. They ate hungrily last night and this morning and they are relatively active. Maybe they were just taking a long break.

I lost another rasbora last night so now I'm down to 3. There's no ammonia or anything so I don't know what's wrong. I'm going to do a water change, but I'm not sure if it will help. Since only the rasboras are dying, do you think it's possible that they have a sickness that only affects rasboras?

Do you also think there's a possibility that the rasboras are starving? My betta competes with them for food and I thought they were eating well but maybe they're not.
 
#11 ·
My corydoras seem to be doing well now. They ate hungrily last night and this morning and they are relatively active. Maybe they were just taking a long break.

I lost another rasbora last night so now I'm down to 3. There's no ammonia or anything so I don't know what's wrong. I'm going to do a water change, but I'm not sure if it will help. Since only the rasboras are dying, do you think it's possible that they have a sickness that only affects rasboras?

Do you also think there's a possibility that the rasboras are starving? My betta competes with them for food and I thought they were eating well but maybe they're not.
Difficult to pin down health issues. This could be something from way back when the fish were initially raised/caught, shipped, in the store, changing to your water parameters...or something genetic. I wouldn't suspect starving; if this occurs, the fish through not eating will get thinner and thinner, usually have difficulty swimming, tend to hang near the surface.

Partial water changes really are miraculous sometimes. They are not going to heal a disease, but they can refresh the fish and strengthen them to fight off whatever.

Haver you explored the rasbora deaths with the store? Are there stock dying off? Are they prepared to replace them?

Byron.
 
#12 ·
I completely forgot about the 2 week warranty at the store. I will take the next dead fish there and see what they say. I'm going on vacation for Christmas soon so I won't be able to do as many water changes as I would like but I will do at least before I leave.
 
#13 ·
Is the other rasboras showing any signs of tummy swelling?
Are they eating and swimming actively?
What symptoms did the other fish show before dying?
Ray
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top