Dead fish + Fungus on mouth

[Deleted]

Hey all,

I've had a community fish tank running for about a year with Danio's, Tetra's, Swordtail's, Raspora's, a Bala Shark, Corys and a Pleco. Pretty cheap but easy to manage fish. I have a Fluval 3-plus filter with carbon, a bubbler and heater. It is a planted aquarium.

A week ago I went to a local fish store to get a Clown Loach and a Dwarf Gourami, with a view of selling the Bala Shark (it was getting too large) and having a pair of Dwarf Gourami's. After a couple days I began to see the Clown Loach chasing everything in the tank, and picking on the side of the Bala Shark and Swordtails. I figured it was just settling in but then the next day the Dwarf Gourami was dead along with 7 other Danio's, Tetra's and Raspora's over the next two days. These are fish I've never had a problem with other than a bout of Ich which was sorted out half a year ago without complication. The Dwarf Gourami and Loach were ordered in and they looked very healthy. I have since returned the Clown Loach.

I took my water for testing and all parameters were said to be fine. The temperature is at 78F and has been consistently. I even brought a new 150W heater to replace the older one, which I rinsed before putting into the tank as usual. Today a couple more Danio's died and now a Serpa Tetra and one Female Swordtail have a white fungus on their mouths. I have done a lot of reading to find out 1. what is is 2. why it happens 3. what to do.

I have done a ~30% water change recently, removing chlorine and chloramine as usual.

I have read that aquarium salt can be used to treat the fungus. Does anyone have any tips as to what proportions to use and also what else can I do to end this Apocalypse in my tank?   

Any advice would be greatly appreciated.

Merry Christmas and Happy Holidays.

[gabor129]

As a general rule you use a tablespoon of salt per gallon of water for a dip. I think you can do a bit higher concentration for shorter dips. I do a 10 - 15 min dip on all my fish before it goes in my tank, no matter where the fish comes from! Working on a quarantine tank too!

1. what is it? - Fungal infection of the mucus cover on the fish, which got worse without treatment and got into the fish system. Most fungal infections are start on the mucus of the fish and if it caught in time it is easily treated.

2. why it happens? - The most likely scenario is that the loach was stressing the fish out as well as damaging the mucus membrane on them which in turn got the fungal infection due to lowered immune system, (stressed out fish), and a way for the infection to get hold of the fish, (the damaged mucus).

3. what to do? - Treat the fish in tank with Primafix, or out of tank dips with salt and/or Methylene Blue. Caution: salt and Methylene blue will kill your plants!!!

Hope this helps, Good luck!

[Deleted]

Thank you for those tips and the great advice gabor129! I really appreciate it.

I would like to go the natural path and use the aquarium salt but I would have to remove all the plants and then replant them again afterward which may stress out the fish more. I'll go with the Primafix you recommend which I have seen a few places.

Thanks again

[gabor129]

You are very welcome! Hope all will work out for you!