Hello from Singapore

[wadjie]

Hi, we have a small fish tank, containing mostly glofish tetra and danio (see picture).

Recently our fishes started to die one by one. Now the latest, our purple tetra is the one sick (see picture and video of the fish posted) -- with its gill slightly opened and its mouth deformed.

Would anyone be able to help -- to advise what disease this could be, and suggested treatment?

p.s. I don't have full water parameters, but I have ammonia alert and PH alert (see pictures posted). Thanks in advance!

 

[Lcc86]

Hi there, what size is your tank and how long has it been running? Have you added anything new? What's your water maintenance routine like?

 

[wadjie]

Tank size is about 17 litre, and it has been running for more than 1 year. Nothing new added recently. We added rabbit snail about 6 months ago and it died 3 months later. After that some more fishes started to die.

Water maintenance is 20% water change weekly or so.

Thanks

 

[TNG]

Welcome to TFF.

I can’t tell what the problem is from the photos, although the video seems to be a fish with bacterial infection.

A general comment is that it’s difficult to keep fish healthy long term in a small tank because good water can change to bad and then to very bad very quickly in a small volume of water. I suspect ammonia and probably nitrite too are high. You have pH and ammonia monitors in there, but one of those 2 only lasts a few month after first use (not sure which one) and the other only lasts about a year, they won’t give you correct readings after that.

Looks like there are 10 fish in there, if the tank is 17L (looks a bit bigger than that) and you change 3-4 litres every week, I don’t think it’s enough to keep the fish healthy, poor water conditions lead to infections and diseases. My suggestion is to change the water daily of about 50%, making sure the temperature and pH of the new water are roughly the same as water in the tank, and find a bigger tank.

 

[Essjay]

In such a small tank, the fish are probably stressed from lack of space as well as potentially poor water conditions. Stress reduces their immune systems so they get sick more easily.

The fish you have need a much larger tank I'm afraid. The tetras need a tank at least 30 inches/70 cm long and danios need at least 36 inches/90 cm. These are glo fish but they need the same conditions as their non-glo ancestors.

 

[Lcc86]

Yes I have to agree with others, whatever the problem is will be greatly exacerbated by the size of the tank, it's small even for one fish. I'd up the water changes to 50% maybe every other day while you source a bigger tank.

 

[wadjie]

Hi, ok thanks for all the inputs and suggestions.

 

[emeraldking]

Thank you for joining...
The deformed mouth could be born defect or a result of an injury. As already been said, from these pics it's hard to tell what may be the cause of those deaths.