Rust like growth on fin

[Erised]

I've been to england for 3 weeks and got back home 2 days ago ... my mum has looked after the fish for me, and well, I thought I'd come home to less fish, but actually came home to more. My otos bred, but all fry got eaten ... so did my danios, but 1 fry survived.

Knowing lil more than this, I figured all would be alright ... but when I got home my tanks looked horrible! I've been depressed all evening and cleaned the tanks the next day. Having a close look at the fish, I noticed some ill ones

1 of my danios has a ragged tail, at the top there's a bit out of it, and at the bottom as well ... strange thing is its in a perfect line. I'm guessing this one would be tail rot. How do I treat this though?

1 of my black neons isnt doing all too well either, when I got home I noticed he hang around the same plant the whole time and got worried already, but there were no signs of illness at all ... today however, he's got this rust like growth at the base of his top fin. It seems to be spreading over his hole top/back instead of just staying on the fin ... I have no clue what this might be. Any help on this would be appreciated!

Another problem I've had for a while now, is my danios having no scales on their gills. Its just a big red spot ... it started on 1 of the 8 I've got, later all 8 had it (this is about 2 months ago) ... I've put them apart and treated them, 3 weeks ago I put them back in the main tank because we were leaving ... 7 of them have healed up, not nicely, but healed ... 1 of them has still got a small red place without scales, but 1 of them hasnt healed up at all yet. It's had more than 2 months and its getting me worried big time now.

There, a lot of stuff going on I'm also worried about 1 of my corries, but except for turning in weird circles I cant see anything wrong yet.

So much that can happen in 3 weeks you're not there *sigh*

Water levels:

Ph - 6.5
Gh - 7
Kh - 5
No2 - 0
No3 - around 10/20

 

[Barday]

Hmm, I'm not 100% sure but the rust like stuff sounds like velvet to me. Its a Protozoan disease which should be treated like ich.

good luck with getting your tank back to how it was

 

[WILDER]

Rust is velvet desease just follow the instructions on the med box.

 

[sylvia]

For fin-rot you'll need to treat for bacterial infections so you'll need to isolate the fish to keep it from causing a re-cycle. Also isolate the fish without scales on its gills (you can keep these two in the same isolation tank and treat them together) and add some salt. Once the treatment is over, you'll want to treat these two for velvet as well- just to make sure you don't re-introduce it to your main tank.