Guppies going wrong?

[Kribi]

We've bought 4 new guppies for our small tank. Everything is balanced, all read-outs in normal ranges, but in the last 24 hours one has died and another is on the way. Symptoms presented include swimming at odd angles (45 degree off horizontal), followed by erratic swimming, rolling, general loss of balance and strength, total lack of co-ordination. The two that have/are suffering don't feed.

Any ideas as to what this might be?

We have a 40 litre tank, running degrees 84F, good filtration, with 6 neons and 6 danios (well within tolerance for size) all of which are healthy.

 

[Panther28]

OK there can be many reasons for this problem. Did you float the bag on the water for 15-20 mins before adding them? Did you add the water they came in? They are stressed and thats why getting sick. Is the tank cycled? What I think you should do is a 50% water change. if you dont think this is right then do a 25-30% water change. people actually say that guppies are very hardy but this is not true at all. A little change can create problems for them. As your fish are sick and not eating you could try the water change. If this does not help. Then I am sorry to say that i dont think anything can help except the water change.

 

[Kribi]

Thnaks for hints. We'll recycle, drop temperature and see what happens.