how do you introduce new fish to an established tank and avoid bringing disease?

[Alyssa]

i have a 10gal with one lone tiger barb ..been probably about a year now. and a lone male guppie with a 20gal all to itself for about 3-4months.

i use to have a school of 5 tiger barbs in the 10gal, but they each died gradually one by one..i'm not sure why bc water parameters were fine...so i was left with the one i have now. i heard a school of 5 or more generally kept the tiger barbs to play with themselves and not harass my guppy so i waited for an established school before i introduced them to my 20 gal...but since i have just one, i never attempted it.

i use to have one of my tanks as a "quarantine tank" for new pets i brought home so if they have disease they wont infect my healthy established tank...what do you all do to prevent spread of disease from new tankmates? I like to let them have a tank to themselves for a month and if they've fine that whole time i introduce them to their real homes.

 

[Lela F]

First of all an established tank is years old, not months. Second the only way to prevent the spread of disease is to quarantine. I am not trying to be harsh, in fact I hate hurting people's feelings, but you need a QT if you are worried about disease. I would also look at the fish at the lfs if you don't have a QT any longer, examine them and see if any signs of disease are apparent. But it will not work for internal parasites. The only way to tell that is if they are scratching against something like rocks or plants with no visible signs of external parasites. If they are not then just take your chances in adding them to your tank. I hope I helped at all.

 

[Rebecca]

If your water parameters are fine, your Barbs might have died because there was simply not enough space for them to move. They do like to swim a lot, and are fairly active, so they do need more than 10 gallons. Moving on though...

I always believe that the best thing to do is to make sure you don't buy unhealthy fish in the first place. Unfortunately, many people look at a tank, go, "Ooooh, pretty fish!" and just pick some at random. I always spend at least a good half an hour looking at the fish I want to buy - even the schooling ones in huge tanks! With the schooling ones, I look at the overall school - Is the school full of active fish? Do they have perky fins? Good colour? Breathing alright? No visible signs of disease? If they all seem fine, I ask the worker to fish out a school for me, and I give each fish in the bag a good thorough examination to make sure that all of them look healthy - and by thorough examination, I mean THOROUGH, not "a quick glance to make sure there's actually 5 in the bag."

The quarantine tank is a good idea. I also make sure to never mix the store's tank water into mine, in case it really is carrying something invisible, but nasty in the water.

Generally though, unless you're unlucky enough to contract a really bad disease, introducing one sick fish into your tank will not kill everything in the tank if the water quality is good. Most fish will be able to fight off sicknesses on their own. Good water quality = good fishy immune systems.