Fin Rot?

[Seandgoode]

Hello everyone please could someone help. One of my male guppies is missing parts of his tail fin and red around the missing areas. I have looked online for other views but all opinions seem to vary. Any help will be greatly appreciated.
 
Tank size: 90L (23.7USG)
pH:8.2
ammonia:0
nitrite:0
nitrate: 40ppm (same as tap water here)
kH: 250.6
gH: 322.2 (Both kH and gH are roughly same as tap)
tank temp: 26c or 79f

Fish Symptoms (include full description including lesion, color, location, fish behaviour): Missing parts of tail fin, and in these areas the fin has red around the edge. He has always been shy and hidden away a bit, although he has been out a bit more recently. He seems to have more attention from the other 2 male gupppies since hiding less and don't know if the damage is from nipping or fin rot. 
Also noticed one of the other guppies chases the female platy too.
Volume and Frequency of water changes: 25% weekly.

Chemical Additives or Media in your tank: easylife easycarbo and profito. dechlorinator seechems prime.

Tank inhabitants: 3 male guppies, 6 female platy (1 just gave birth but only 1 fry survived) and 1 male platy.

Recent additions to your tank (living or decoration): Other than one new born, none.

Exposure to chemicals: none

http/i1375.photobucket.com/albums/ag450/seandgoode/fish3_zps098167e3.jpg
 
http/i1375.photobucket.com/albums/ag450/seandgoode/fish1_zps783adb08.jpg
 
http/i1375.photobucket.com/albums/ag450/seandgoode/fish4_zps4467f2c8.jpg
 
http/i1375.photobucket.com/albums/ag450/seandgoode/fish2_zpsd4732850.jpg
 
 

 

[star4]

It is hard to be 100% sure from the pictures, but it looks more of fin nipping damage to me rather than fin rot. Keep a close eye on it look for signs of it becoming worse, more ragged and white edges to the rest of the tail and fins.

 

[Seandgoode]

Thanks for the reply, I will keep an eye out. I am nearly finished cycling another tank so might pop him in there when it's ready. Thanks again

 

[star4]

 

[Seandgoode]

Hi have been keeping an eye on him and doesn't look to be any worse. Red edges have subsided and seems social. Just waiting for Tail to heel, thanks for the advise.

 

[star4]

Sounds good . an extra small water change in between normal water change wouldnt harm

 

[Seandgoode]

Unfortunately Mr guppy died the other day. I don't think it was fin rot in the end and was a case of nipping. Water tested every day and readings remaind the same so I can only think he must have been bullied.