Bought New Fish, Those and My Old Fish Died ...

Question
QUESTION: Hi, I have a 45 gal. freshwater tank that had 2-3" Orandas and a Calico
Shubunkin (I think).  Well, went to Walmart and bought a Black Moor and
another Shubunkin and within a week, they all died.  I use the Stress Coat,
keep the H2O fairly clean, they have plenty of O2 with a Penguin filtration
setup.  I had 5 fish and now I have none ... any ideas?  Do I need to change all
the water in the tank before I put in new fish?  What kind of fish do you
recommend?  Thanks for answering.

ANSWER: Hi Michael,
Sorry to hear about the goldfish.
The most likely culprit was ammonia buildup that caused all your fish to perish. If this is a recently setup aquarium, it doesn't yet have the special bacteria colonies (who are responsible for converting ammonia into less toxic compounds) established which can take several weeks. And what's worse is goldfish produce a large amount of ammonia in comparison to their size. Remember fish in aquariums are swimming in what's equivalent to their own toilet bowl.

So how do you battle this? Well, you have to add just 1 very small goldfish (if you want to go with goldies again) to your tank. Be sure to have test kits for ammonia and nitrite and nitrate as well. And be prepared to make plenty of partial water changes. You need to "cycle" the tank before fully-stocking it with a lot of fish. Cycling basically just means adding "cycling" fish which produces ammonia to get the bacteria started. The bacteria convert the ammonia into nitrite which is still toxic. But fortunately, more bacteria develop to convert the nitrite into non-toxic nitrate. When cycling your tank, you just keep your "cycling" fish in there -until- the tank finishes cycling which is indicated when your water tests out as follows- Ammonia-0 Nitrite-0
This might seem really confusing at first but it's not all that complicated once you break it down.
Just remember that clear looking water doesn't guarantee ammonia-free water. You can't see ammonia at all, but you can test for it with simple test kits from your petstore. I recommend the liquid test kits which are much more accurate and easier to use than the strips.

Plenty of water changes are essential when cycling your tank (cycling can take about 3-6wks) this is to keep your cycling fish safe. There's no reason why the fish should have to suffer through high ammonia during cycling and that's where the large water changes come in. Make sure to do a 30-50% water change whenever your ammonia goes above 'safebounds'.
Water changes will not disrupt the bacteria's growth.

If you'd like to try a different kind of fish other than goldfish. I recommend platies, guppies, swordtails, as well as Tetras, Barbs, Danios and rasboras. Most all of these fish are good beginner fish (if you are a beginner) and they are great starter fish...Just be sure to do some research on any fish you plan on keeping beforehand so you can avoid common mistakes or problems.

With cycling your tank with the smaller fish. I'd use about 4-5 Black skirt tetras...These are by far the best cycling fish around. Or you could also try 6-8 Zebra danios or 5 platies which are also good cycling fish that can withstand some poor water quality issues. But just don't make them have to endure horrible conditions, and keep up with water changes and testing your water during cycling.

Once you get ZERO readings for ammonia and nitrite you can slowly and gradually begin building up your fish numbers. Only add a small group of fish per week or so and test your water the day after adding them just to make sure.

Before adding anymore fish, the water likely has a lot of ammonia in it so I'd do a water change down to the gravel and refill with fresh dechlorinated water before adding anymore fish. Make sure to never use chemicals in or around your aquarium.

Best of luck and I hope this helps!!
Karen~

---------- FOLLOW-UP ----------

QUESTION: Hi Karen, but this is a tank I've had set up for at least 2 years and accounting
for evaporation, the tank had about a 30% water change done just the day
before, which I always do before I add new fish.  Thanks for the ammonia  
test suggestion.  I'll try that, but I'm still worried.  Haven't bought any new
fish yet.   Do you still think it's only ammonia?

Mike

Answer
Hi Mike,
If the aquarium's been setup for 2 years it should certainly have been well-established and cycled a long time ago. A water test wouldn't hurt still. Usually when fish all die off so fast it's water quality related. It can be a very common problem especially with goldfish. High nitrates may even be part of the problem. Or is it possible any chemicals could have gotten into the aquarium? Soap or anything else?

I really hope this helps!!!
Hope you can get things straightened out.
Karen~