Help with Harlequins

[acsrmjq]

Hi All,

I'm new to tropical fish keeping and I have tried to prepare and research properly before introducing fish species. I am however having some problems with Harlequin Rasboras that I have been introducing. I initially added 6 to my 32g tank. They initially all seemed to settle in well but one, smaller specimen died after a couple of weeks. Water parameters seemed fine (see below) so I assumed I had just purchased a small, weak fish. I decided to add a 3 more a week later. These again seemed to settle in fine, but in the last week I have now lost another 3 (two from the new batch). One death was sudden but the others went in a familiar pattern of becoming withdrawn from the shoal, not eating and getting thin before dying. The fish were introduced using floating bag/gradual water change' method.

My water/tank details are:

Juwel Rio 125 with Bioflow 3 filter, including Cirax, running for two months.

Ph: 7.6
Temp: 26 Celsius
Ammonia: 0
Nitrites: 0
Nitrates: 20ppm although I must confess it was reading 80ppm when first one died. I have since introduced API Nitra-Zorb.
I change approx 33% of the water once a week
Tank mates: 6 Cherry Barbs (which are doing well).
The water is moderately hard.

Now I know from my research that Rasboras live wild in softer, acidic water but the general consensus in my online research and info from the LFS is that they will adapt readily to my harder, alkaline water (my LFS is only a few hundred metres away so presumably has similar water).

So, have I made a mistake in adding Rasboras? Am I doing anything incorrectly? Are my remaining 5 Rasboras likely to be OK ( the shoal appear to be thriving at present)?

Any advice much appreciated.






Matt Quish

 

[ScotJudd]

Hi. I have a shoal of 9 rasboras along with about 50 other fish (tetras and Cory's). My water is soft, buffered up to Kh 6 / Gh 6. Ph 6.6-6.8. Temp 26C. Ammonia 0, nitrite 0, Nitrate <10.
Introducing new rasboras to the tank is hit and miss. I have lost a few despite 4 week quarantine. However, the remaining rasbora are doing really well.
Assuming your LFS water is the same as yours is probably not right. My LFS, only 10 miles away has hard water, fairly alkaline and unfortunately nitrates of 80+. Fish are stressed when you get them and may have been in less than ideal conditions for some time.
I would not use products to reduce Nitrate. Providing your source water has no or little nitrate then water change frequently with conditioned water to reduce nitrates.
Fish do acclimatise to less than perfect parameters but some losses are inevitable. You said your remaining fish are healthy so I would add another 5 to boost the confidence of the shoal against the cherry barbs which can be bullies. A few weeks in a quarantine tank is ideal to allow the new fish to settle in without having to deal with other tank inhabitants. Also it avoids introducing deceased fish into your main tank. I appreciate not everyone has a QT but they are a very good idea and worth thinking about.
Adding bog wood would help acidifying the water naturally. Live plants also help stabilise a tank and give your fish cover when they need it.
Don't give up on the rasbora, they are great fish.


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[acsrmjq]

Many thanks for taking the time to provide this useful advice. Note that I do already have Plants and bogwood but I shall certainly look to take up your other suggestions. Regretfully, the QT is the only one I can't really manage. My house is pretty small and I don't have room for another tank.

Thanks again.


Matt Quish

 

[ScotJudd]

You're welcome.


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