Velvet Disease

[erwolfe]

I have a 55 gal tank with 1 roseline shark,  5 diamond tetras, and a gold gourami. I added 2 cories about 3 weeks ago. I do a 50% water change about every 3 weeks (i had just done one the day before adding the cories). I think my fish have velvet disease as 3 of my diamond tetras are dead as well as my shark and the remaining all look rusty and filmy, and are acting crazy. I am sure I have been over feeding as i have been worried about the cories not eating (i know better, so i have no excuse) 
I'm thinking they may be too far gone to medicate   but I am not sure. I am going to the pet store as soon as it opens today but I don't even know if they will last that long. ANY suggestions are appreciated

 

[DoubleDutch]

What are the waterparameters. Velvet doesn't kill in a few days. Could be ammonia / nitrite due to the pollution.

 

[DrRob]

Sorry to hear about this, I hate velvet.
 
Treatment is very similar to ich, although the blackout section of treatment is more recommended as velvet is somewhat photosynthetic.
 
You need to kill the bug in it's free swimming stage, and various meds help with this (remember to get any carbon or purigen out of your filter when you do this). If you have a hospital tank that you can remove the remaining fish to it may help to keep any copper based treatments out of the tank.
 
Before you can get treatments in there are 3 things you can look at, 1st is that raising the temperature will encourage velvet to progress through the lifecycle, but you'll need some treatment going in for this, but it's best done gradually so you may win overnight with this and get some meds in as soon as possible. Velvet also damages the fishes gills, and salt is often recommended to help the fish breathe, although cories aren't massively salt tolerant. You'll also want LOTS of surface agitation as you turn up the temperature to try to get as much oxygen into the water as this is often what will kill the fish. Finally it's worth, especially if you're worried about overfeeding, making sure that you have good water parameters, as nitrite levels will make velvet far more lethal as it irritates the gills even further. Fresh water in a hospital tank may help here if it's an option.

 

[erwolfe]

cant check the parameters til the store opens one article i read on velvet disease says symptoms may not be visible until it is too late though. 

I do not have a hospital tank set up, but I am assuming i would have to set up a tank and wait for it to cycle before i could use it

 

[DrRob]

Nope, set up a tank and throw a lump of mature media in it's filter, especially if your stock is low (sadly relative to your previous stock) on the hospital tank and you're happy to do daily water changes on the smaller tank (which will also help a lot). Cheaper to medicate and easier to supple lots of fresh water so they sometimes pay for themselves. Just remember to keep the main tank ticking over with something to keep the ammonia cycle going on the rest of the filter.

 

[erwolfe]

Thank you so much for the help, how do I kill off the velvet in the main tank then? Do a huge water change and black it out?

 

[josh63762]

firstly large for now do a 50% water change a 50 % change every 3 weeks Is not often enough you should do a 25-30% change every week minimum! you do not need to let the tank cycle as mentioned above simply throw some filter media in. best of Luck!

 

[DrRob]

Thank you so much for the help, how do I kill off the velvet in the main tank then? Do a huge water change and black it out?

 
Given 10 days or so without a host, particularly with the temperature turned up, they'll die off anyway.
 
There are differing opinions as to how long it takes.