Strange Behaviour By Corydas Sterbai

I have two Corydas Sterbai that have happily been in my tank over the past nine months but all of a sudden they are now hiding inside an artifical log and don't appear to move around as they used to. So my questions would be is this behaviour normal, could they be breeding or have I got a real problem?

Other fish in the 125 litre tank are swordtails, mollies, tetra and pencil fish but they have always been great in each others company, however, after a recent bout of hot weather I have lost quite a few mollies to swim badder issues and as a result have had to use some recommended treatments to get on top of this.

Hope this finds someone who can help.

Colin

Thanks for that feedback Sue and I'll monitor their progress following a water change today. They've not had any mates of the same species since they were bought so was a bit surprised by the recent activity especially aas one of them just seems to be facing upwards all the time instead of lying flat but as you say the chemicals may have played a part. I also added aquarium salt in an effort to help the mollies so perhaps they didn't like that either, however, in my defence this was following advice at a specialist store.

Colin

Cories are one of the salt intolerant species, as Colin has said. Don't believe everything a shop tells you.

Mollies are hard water fish, and like a high pH. They can suffer if kept in water that's too soft and acidic. A lot of people believe they need salt in their water but this is not strictly speaking true. They need a lot of the stuff that makes water hard rather than plain salt. Marine salt can be added to their water - in fact some types of molly can live in full strength sea water - but this is not plain salt but a mixture of several salts.

But cories can't take a lot of salts of any type.