Fish Dying One By One

[JamesW]

We have had our tank since Christmas

This is what we currently have in our 120 litre tank in order of when they were added (number of deaths in brackets)

5 Cardinal Tetra (1)
6 Harlequin Rasbora (0)
5 Pentazona Barbs (0)
4 Green Tiger Barbs (2)
2 Red Platies (2)
1 Bristlenose Catfish (1)
0 Honey Gourami (2)
5 Swordtails (2)
3 Black/Yellow Platy (0)

After the Pentazonas were introduced we got a bout of whitespot (around February) and this was treated, but unfortunately we lost 1 tetra. About a month after the whitespot episode we started slowly introducing a few more fish until April when we lost a couple of fish and since then they are dying at the rate of about 1 a week.

The fish become very inactive, don't feed and slightly lose their colour 24-48 hours before death, they don't show any physical signs of illness. During this 24-48 hours they don't go and hide but stay out in the open. All the other fish in the tank are swimming around and feeding normally.

All the water parameters are normal and we change 25-40% of the water every two weeks, depending on how much muck is lifted from the gravel.

All the early fish we added at the beginning seem unaffected it is just the ones we have added over the past few months.

Any ideas would be greatly appreciated.

 

[scooterchick]

Looks like you may be overstocked, there's a lot of fish in there. I think a water change every week for those amount of fish may make a difference. There's also the possibilty that your tiger barbs could be terrorising the other fish. Do they bully them?

 

[scorphonic]

O man, you look to be severely overstocked...31 fish in a 120L? I've only got 20 or so in my 180L + 100L.

Do water changes, test your water conditions, you could add a small amount of aquarium salt and possibly turn the temp up a degree or two to 28 degrees to see if the fish get better, if its a bacterial problem that you have yet to identify

Doing a water change only every two weeks is not the way to go either. You should be aiming to do a 25% water change every week..especially with the amount of fish you have in there.

You say that the water is ok...can you tell us what values the water test kit is giving you?

 

[JamesW]

Looks like you may be overstocked, there's a lot of fish in there. I think a water change every week for those amount of fish may make a difference. There's also the possibilty that your tiger barbs could be terrorising the other fish. Do they bully them?

The tiger barbs seem to chase each other, but they never bother the other fish, every time I've added new fish I have listed to the LFS what fish we already have and they've never said there's a problem adding more.

 

[JamesW]

O man, you look to be severely overstocked...31 fish in a 120L? I've only got 20 or so in my 180L + 100L.

Do water changes, test your water conditions, you could add a small amount of aquarium salt and possibly turn the temp up a degree or two to 28 degrees to see if the fish get better, if its a bacterial problem that you have yet to identify

Doing a water change only every two weeks is not the way to go either. You should be aiming to do a 25% water change every week..especially with the amount of fish you have in there.

You say that the water is ok...can you tell us what values the water test kit is giving you?

Temp is 26-27 degrees, so I'll try turning it up slightly with some aquarium salt. The water change probably averages every week and a half, sometimes we do it weekly, and sometimes fortnightly, depends on time really. Looks like we'll be doing it weekly now.

Values are:
PH 7.2
Nitrite 0
Ammonia 0
Nitratte between 10 and 20

 

[vinylman]

Don't take any more advice from your LFS. Are they really going to talk you out of spending your money?. Whatever you want to know, or are thinking about doing to your tank, ask here first. I'd seriously think about taking some fish back to the shop, starting with the Tiger Barbs; they really need to be kept in groups of at least 5/6 and need a LOT of swimming space. The Swordtails will get to around 3'' too. In a 120 ltr tank, you need to concentrate on the smaller fish, but have them in decent sized groups. Please vac your gravel and do a water change every week, as noted elsewhere.