Need more info.
Size of tank in gallons or litres.
How many fish and which type.
Can you post your water stats please.
Did the dead fish show any symtoms before the died.
Hard to say really.
An fish look bloated or skinny.
What does it look like when the fish go to the toilet.
Less active can also mean quite a number of things.
Did he stop eating.
Did he rest to oneside.
Did he look pale or darker in colour.
Fish can stop eating for a number of reason, stress, old age, internal parasites, bacterial infection.
How long did you climatise the new guppy for.
Keep a look out for when the fish go to the toilet.
same time we always do, we had this tank for 6 months and these are first deaths and its upsetting they all got names. thanks for help i will keep u posted
Always test the bag water in ph and temp this way you know how long to climatise for.
Keep a look out for when the fish go to the toilet.
Lost any fish to be skinny or bent spines.