caustic odor from fishtank

Question
Hi,
I just set up a new tank.  It's a 20 gallon tank with two tiny "telescope" goldfish in it.  I had them in a much smaller tank, they were getting sick.  I got this new tank, along with a filter that sits in the tank, rather than hanging on the side.  Before I put them in the new tank, I alleviated the swim bladder problems, but one got sick from what looks like too much ammonia.  I switched them to the new tank and the fish seem very happy.  When I got this new tank, I also got an ammonia meter and a temp gauge.  The tank ranges from 69 - 71 degrees usually and the ammonia meter has yet to go up, at all.  I think this might be from the biozyme I added, trying to keep the ammonia down.  The other day i noticed a horrible, toxic like smell.  I thought it might be my cat's litter box, but no I realized it was the fish tank.  I changed about 25% of the water yesterday, to try alleviating some of the smell.  The fish seem perfectly content, the problem is this smell is so bad, it's making me sick.  My apt is tiny, and I've had a non stop headache and nausea since yesterday.  Today the smell is less like ammonia and more like kerosene or something.  What can I do about this?


Answer
Hi Amanda,

I hate to tell you but 20 gallons is far too small for two goldfish.  You really need at least a 30 gallon tank with no less than a 60 gallon filter, the larger filter being much more important.  You also need to make sure you have a powerhead or powerful aerator, something to move the water current as goldfish need tons of oxygen.

I would not rely on that ammonia gauge.  They are quite frankly, well, useless.  You need to purchase an API Freshwater master test kit and test with liquid for ammonia, nitrites and nitrates.  It's $30 well spent as it's extremely accurate and the kit lasts well over a year.  Ammonia and nitrites should always be 0, nitrates 5-20 ppm.  Testing this is the key to your issues.  Biozyme will help but it won't prevent the coming ammonia spike if the new tank wasn't laced with items from the old tank.

How did you change everything over?  Did you lace your new filter with old filter media?  Did you use your old gravel and old water?  If you didn't the tank will likely start the cycling process all over which could not just be causing the stink but could and will kill the fish.  You will need to do 25% water changes at least 3 times a week to keep the ammonia and nitrites down.  I would double dose a product called Seachem's Prime during this time in place of your usual water conditioner, I would definitely use API Stress Coat and Tetra's Easy Balance.

Make sure you wipe the strips on your tank down too.  Sometimes the chemicals in the conditioner get onto the black (or oak or whatever color you have) strips that line the tank top and bottom and cause a funky smell.  Wipe this down really well with a towel and some water with a touch of distilled vinegar (DO NOT GET THE VINEGAR IN THE TANK!).

Good luck : ) April M.