I had a dwarf gourami in my tank for several weeks and it was healthy, as were the rest of my fish, including regular gouramis.  I decided to add another dwarf gourami.  I purchased another one from the local pet megamart.  My quarantine tank had an algae explosion and I hadnt dealt with it, so I stupidly decided to put the new dwarf in the tank.  For a few days everything was fine, but one morning I looked in and saw one of the dwarfs lying on the substrate gasping.  There really wasnt anything I could do, as I still hadnt taken care of the quarantine tank.  I thought, well if he dies, I can return him and get a new one.  Later that day, my other dwarf was dying as well.  My non-dwarf gouramis were doing fine; and still are several days later.  I thought this could not be a coincidence and started researching online in forums and sites.  It would *appear* that the new dwarf had [Dwarf Gourama Indovirus (DGIV)][1] and passed it to the other dwarf.  It is a dwarf only disease, which makes sense, as my other gouramis are fine.  I tested my water and it was acceptable, so thats a plus.  I brought the dead dwarfs back to the store and they refunded my money.  I looked at the remaining dwarfs in the store and they looked sickly as well.  This observation makes me feel fairly confident if was DGIV.

If I *were* to get more dwarf gouramis (I found a better non-chain store), do I need to wait a specific period before the virus dies out?  I do weekly water changes of 12.5% and I have a small UV filter running.  

I definitely prefer answers with sources to back them up.


  [1]: https://www.petcha.com/fish-viral-disease/