Can someone tell me what is happening?? Fin rot? Fungal?

[jesslord45]

Ok so first off tank is 15 gallon rectangle, freshwater, live and fake plants with various tank decor, gravel substrate. Bubble air stone, heated and aqua clear 20 hob power filter.
Parameters are nitrate and nitrite 0, hardness soft, chlorine 0, alkalinity moderate, ph 7.0-7.2 ammonia 0
Now the issue.. I started out my tank with 3 Rosey white tetras and a rainbow shark. Everything was fine for about 3 weeks then my shark started terrorizing the tetras to the point they were always being chased and after some research I learned I had no business with a shark in a tank that size. I ended up bringing the shark back to my LFS and got 2 red tail black variatus. this week I went and got 1 dwarf gourami and 2 fancy guppys. I noticed when I put the guppys in the tank they were acting really weird clamped fins and looked like they were almost having seizures the next day I came home from work and one of the guppys was dead half eaten in my tank and the other one had a huge chunk taken out of his tail. Culprit gourami. So last night I brought the guppy that was still alive back because I feared he was next. This morning while feeding I noticed all of my tetras besides one have completely shredded fins and all of them have a grayish black on the outside of the back fin. And the baby red tail looks like he either got nipped or he is getting something as well?? I’m lost at what to do I did put melafix in the tank and aquarium salt but I don’t know if the gourami is causing stress or being a bully or what is happening really.. sorry for the long post but any help would be much appreciated. Pics attached as well. Thanks in advance

Sent from my iPhone using Tapatalk

 

[fishlover22346]

that would be fin rot. this means their fins have gotten nipped at, and bacteria got on the fin, causing the fin to rot away. to treat this, make sure your water is absolutely perfect, and put some salt in the tank, I would try natural sea salt from a grocery store, or aquarium salt for diseases, which is at most pet stores. do 1 tablespoon of salt per 5 gallons of water. Sorry for the late reply, I hope your fish are doing ok.

 

[NickAu]

put some salt in the tank,

Salt is not needed for fin rot.

I would try natural sea salt from a grocery store,

Please dont use any old salt, Kosher salt is cheaper than Aquarium salt.

 

[fishlover22346]

while it may not be needed it supplements the fish and helps kill bacteria on the fishes fin

 

[Fishi123]

use fin rot treatment and they shall be fixed up in no time.

 

[fishlover22346]

that works too, like malafix

 

[NickAu]

Melafix?

All Betta Owners Read!!!!! Melafix Alert!!!!!! Read!!!!

To cure finrot you dont need gimmicks or potions ALL you need is lots of clean water.

 

[fishlover22346]

true, that’s the main cause of fin rot, so yeah, if your water is absolutely perfect, then sure, you might want to add something, in my opinion, but usually fin rot doesn’t happen in just perfect water.

 

[NickAu]

I keep Female Bettas in a sorority tank and they sometimes take a chunk out of each others tails, I never have problems with fin rot because my water is perfect, I do a minimum of 50% water change every week. The only thing I add to my water is Indian Almond leaf.