Neon trouble?

[Fifi]

I have 6 neons and have kept them since September.

I noticed one tonight who has a swollen abdomen and is swimming with head pointing down at eight'o'clock position in a sort of short darting movement.
Nothing else is visble,colors are bright and all other fish in tank look well.

Other fish: 1 pair of dwarf gouramis,1 kissing gourami,1 sailfin Molly.

my readings are ok and I change 40% water twice per week. The water is ph 8 around here.

If you have any Ideaswhat could be the problem,thanks for your help

Fifi

 

[Obsidian]

pH of 8 is not exactly what neons would like... they like fairly soft water. As for the one swimming head-down.. perhaps gravid with eggs? Females can be identified by the blue stripe being more curved. I have one female that always looks about ready to pop, and she swims that ways a lot, but they are all healthy.

 

[Fifi]

I think the problem was that i had just fed them and they had eaten too much in one go!

Theyr'e fine today I guess I worried too soon, I am always watching them as I have had bad experiences with illness in thre past.

I guess my fish just gorged themselves on an "eat as much as you can meal deal!"

Thanks for your help!

Fifi