Neon Tetra Problem

[doresy]

Hi, I have 6 small Neon Tetra 'growing on' in my 34 lt AquaOne. Tank mates are 3 Pigmy Cory and 4 Endlers.

Water test shows 0ppm ammonia, 0ppm nitrite and 40ppm nitrate (from the tap )

Tank has been running 3-4 months (after a fishless cycle) and current stock for 2 months

Problem being that ONE of the Neon Tetra has developed this patch. Other than that it feeds well but does tend to swim slightly 'nose down'

Have treated (twice) with Interpet No.7 (anti Slime & Velvet) as that is what I thought it was but no effect.

Advice please

Here's a photo.......

 

[WILDER]

Never medicate till you no what you are medicating for.
The patch is it bleached out in the red stripe area, just want to make sure it dosn't look fluffy.
Any lining of black around the red stripe area.
Are lumps that go to a point on the belly area.
Swimming oddly.
Has the neon left the shoal and seem restless.
Any bloating in the tummy region, or the eyes bulging out.

 

[doresy]

Never medicate till you no what you are medicating for.
The patch is it bleached out in the red stripe area, just want to make sure it dosn't look fluffy.
Any lining of black around the red stripe area.
Are lumps that go to a point on the belly area.
Swimming oddly.
Has the neon left the shoal and seem restless.
Any bloating in the tummy region, or the eyes bulging out.

1) ok wont do that again
2) Yes in the red and blue area but not fluffy
3) No
4) No
5) Swims slightly nose down
6) Leaves the shoal but not restless and feeds well
7) No and no.

..................................................thanks

 

[WILDER]

Hard to make out in the pic but does it look a creamy white in the red and blue area.