Two Guppies Fin Nipped/rotten/torn?

[SandraNewbie]

this is not an emergency so I'll put it here.
Tank size: 100-110L
pH: 7.4-7.6
ammonia: 0.00
nitrite: 0.00
nitrate: 5-10pp, (gets closer to 15 by the time I water change)
tank temp: 25-28 C (tank has started gettting colder overnight)
Fish Symptoms: I have two male guppys in my tank (google guppy red leopard tail and the first image is what they look like) which have always had slightly frayed fins, but I'm worried that the fraying is slowly getting worse. There's no white edging on it noticeable and they are behaving normally, pooping normally and still randy as hell.
Volume and Frequency of water changes: 30L weekly minimum (60L regularly and 90L once when I had a nitrate spike)
Chemical Additives or Media in your tank: Stress Coat+ water conditioner
Tank inhabitants: 5 Bala sharks, 1 female BN Plec, 11 Guppies (6 female 5 male). [no comments on the tiny tank for balas, I've lost a tank recently]
Recent additions to your tank (living or decoration): Tank was recently rehomed to this tank due to a water leak in my 7.5'
Exposure to chemicals: Bala food was dropped in tank about a week ago causing a nitrate spike between 80 and 160.
Digital photo (include if possible): Will do.
Essentially, I want to know if I should Isolate them into a hospital tank and do anything to try and let their tails grow back. I've never had torn fins on any of the guppies before but these two both have tears (not like chucks but thin rips, they go aout as deep as the first full black line on the image I recommended googling).

What do?

 

[thereverendturtle]

I would separate them and add some salt, to help prevent fungus/bacterial problems. Have you noticed anyone chasing them? Maybe the balas getting a little nippy at feeding time?

 

[SandraNewbie]

Balas don't interact with the guppies at all, even when they're all fighting over the algae tabs. One of the balas is getting a little picked on in the temporary tank, so I'm having to direct feed him a little, to make sure he gets some.

but no, I've notice no nipping behaviour.

 

[SandraNewbie]

Ok, so I've moved them to a 30L hospital tank with established filter, raised temperature to 28 degrees (maybe 29) added some aquarium salt and a weeks worth of Melafix (had to do the dosing in 4 days rather than 7, but the guppies coped well)

How will I know if it's worked?

 

[snazy]

Why are you raising the temperature? Most bacteria thrive in higher temperatures so if they do have bacterial infection this will make them worse. Temperatures should be raised only for possible parasitic infections and that's when you know they don't have an additional bacterial infecttion. I doubt it they have anything if you can't see any other signs but thorn fins and they should recover with regular water changes in a cycled tank.

If you use Melafix, it's better to be used with Primafix together as Melafix is for gram positive(less likely bacterial infections) and Primafix kills mostly gram negative bacteria which cause the majority of bacterial fish diseases.