Restocking?

[Lizzie71]

Earlier this week, I lost 4 of 6 hengel's rasboras. This was following a power cut and the filter and heater being off for about 8 hours, a week ago.

I have had traces of ammonia in the tank this week, never above 0.1, but it indicates that the filter lost some of its bacteria in the power cut, and the poor water quality probably explains the deaths.

I have done two large water changes this week and I seem to be getting on top of the ammonia issue. The remaining fish, which had been very subdued, are now swimming happily again. If tests continue to be OK over the next week or two, I want to replace the dead fish.

Question is, should I get more hengel's rasboras? The remaining two don't seem stressed at all without their friends, but then again, I don't really know what to look for. Or could I get something different?

Tank is 34litres. Current occupants are 3 platys (plus 2 fry which I won't keep once they reach maturity), 2 ottos and 2 hengel's rasboras. Current readings are

ammonia 0
nitrite 0
nitrate 20
ph 7.5
temp 27

I was considering maybe a small gourami instead of the rasboras. Or could I get a different type of rasboras, such as harlequins?

 

[chibi]

I wouldn't recommend a gourami for your tank because they can be territorial, especially in a small tank like yours. They'd likely harass your other fish. I have never heard of the type of rasbora you have, so I can't help there. Harlequin rasboras are pretty hardy, though. I'd get 5 of those. This may seem like a lot, but they don't add to the bioload as much as other fish do and they like being in schools.

 

[mark.w.jones]

The reason you lost so many fish in such a short space of time was because you were overstocked. When things go wrong in an overstocked tank they tend to go very wrong unfortunately. Your filter would have been struggling to deal with the waste from that many fish in such a small tank as it is. I have experienced 12 hour power cuts in the past but as I was stocked to the correct level I didn't lose any fish. Your tank only has just enough space for the platies and otos you currently have and would be fully stocked just with them. But you had another 6 fish on top of that in there so I'm no surprised things went as wrong as quickly as they did. In all honestly you would certainly have had problems with water quality anyway had you not had the powercut. So look on it as a blessing in disguise .

I would advise that you remove the platies completely as otherwise you will constantly have to remove fry which will again over stock your tank when they appear. Livebearers are never a good idea in such a small tank IMO. About the best stocking you can get in such a small tank would be:

4 Otos (These should ideally be in a bigger group than this)
4 (Hengels Rasboras)

That is all you have room for and the rasboras are a better option as you won't end up with loads of fry. Want more stock and more variety? Then a bigger tank is your only option I'm afraid.

 

[Lizzie71]

The platys are all female so fry should stop being a problem soon - one was pregnant from the lfs, but it won't happen again.

I appreciate your advice, but the platys will be staying because they are my children's pets and even have names. Maybe I'll just leave things as they are and not add any more fish to what I currently have.

 

[mark.w.jones]

The trouble is that you are then keeping two species which need the security of a school only as pairs. Schooling fish kept as singles or pairs live an uncomfortable and often stressed existance without the safety of a larger group. The final choice is of course yours but if you want to keep the platies then I would advise you take the rasboras back to you LFS and buy 2 more ottos. You will then be about perfectly stocked. If you go for this more balanced stocking option but want a bit more interest in your tank I can highly recommend amano shrimp. The kids at the school where I work love ours and they are far more interesting to watch than fish IMO. They also produce minimal waste so are fine to add to a fully stocked tank.