White Spots Showing On Tail-fin Rot?

[romanianfishman]

So I have 5 glowlight tetras which I noticed after not treating them entirely developed again a white fizzy spots at the end of the tails.

I used Pimafix and Metaflix without carbon which caused it to disappear and repair the fin. I stopped thinking it was finished but occurred again

I just want to know if this is fin-rot? I have driftwood and all real plants.

I have 3 rummynose tetras which show no signs and 4 guppies which show no signs.

The water parameters after a week without water change are consistent pH:6.6, Nitrate:5 ppm, Nitrite:0 ppm, Anmonia: 0 ppm: KH:89.7 ppm: and GH:179 ppm. I change water on 15 gallon tank once a week to prevent any issues.

Glowlights are from petco as are guppies. I adopted rummynose tetras which are surprisingly strong.

Is this fin rot?

 

[Liam_syay26]

Can you put a picture on

 

[romanianfishman]

 

[romanianfishman]

 

[Rojer Ramjet]

Looks like fin damage from nipping; hard to tell - so difficult to take photo's of fish.