new fishtank

Question
Hello,

I purchased a 10 gallon tank about 4 weeks ago and bought 4 goldfish.  3 of them have already died (the 3rd one died yesterday).  I did a 25% change about 5 days ago and the two remaining fish appeared happier but one died yesterday.  I just did another 20% water change today.  my water is cloudy.  When i did the water change, i noticed that it wasn't clear either--had a yellow/brown tint.  THe remaining fish likes to stay in one bottom corner of the tank.  THough at times throughout the day, it appears to be lively.  I am concerned because the water has not cleared up yet and am afraid that my fourth one will die as well.  WHat should i do?  (Oh, I also changed the filter yesterday)

Answer
Good evening Linda, thank you for your question.

The problem you are experiencing has a name, although it is not a disease. It's called New Tank Syndrome. It goes like this: you buy a new fish tank. Unaware of the cycling process that needs to take place, you buy a new fish tank and fish that same day or the next. Ammonia builds up as uneaten food and waste accumulate without bacteria to process them, causing the telltale cloudy water. You do a big water change, a necessary evil, since you need to remove the toxins from the water. However, the frequent water changes forestall the cycling, and this process repeats for weeks, with the fish in distress throughout. What to do? Well, first, read here to learn about cycling:
http://freshaquarium.about.com/cs/biologicalcycle/a/nitrogencycle.htm

Then, read here about what to do when you need to cycle your tank but have fish already in your system:
http://www.fishforever.co.uk/cycling.html

The article is about fishless cycling, but at the bottom it will tell you what to do if you have (oops) already added fish. There is more that you should know...

For example, 4 goldfish would have soon outgrown the 10 gallon tank. Goldfish should ideally have 20 gallons to themselves, but one goldfish will be okay in a 10 gallon tank for a while. Since they can live over a decade with good husbandry, a larger tank is worth the investment later on. Another issue is that goldfish are massive waste producers! Besides the lack of physical swimming room, 4 goldfish in a 10 gallon tank would have taxed the filter beyond its ability to function properly.

Ideally you should have 2 filters hanging on the back, each rated for a tank of 10 gallons or more. Carbon cartridge filters are okay, but when you discard one and change it, you also discard valuable bacteria that has colonized on the floss. That is why two filters, cleaned on an alternate schedule (making sure both are cleaned weekly or at least twice monthly) is highly recommended.

I hope you gathered from those articles the fact that you need a water test kit. Please do look into one if you don't have one as of yet. Liquid test kits are the best value and much more reliable than strips. On a regular basis, test for ammonia and nitrite, both these levels should be at 0 ppm. Nitrates should be kept below 20 ppm at all times. Vacuum the gravel 2x a month to keep the nitrates down, even a healthy, cycled tank can have high nitrates due to an abundance of decaying material in the gravel, decor, etc.

Never wash your filter media or gravel in tap water! The beneficial bacteria that you need in order for your tank to stay in balance, will be wiped out by the sanitizer in your municipal water. (Chlorine kills all bacteria, even the good kind, the same way antibiotics do.) Instead, use aquarium water from your weekly (or twice weekly) water changes. You should be changing 2 gallons a week at the least, but up to two 50% water changes a week would be just fine. Just don't perform 100% changeouts in one sitting, except in an emergency such as a poisoning or overdose of medication.

Read this article on feeding to ensure your goldfish stay healthy and free of any buoyancy issues:
http://www.wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm

Also, check out http://www.kokosgoldfish.com and http://www.goldfishparadise.com for more goldfish care info. I would also take time to read the linked files above at Wet Web Media, their site has a Q&A component, too. Marvelous sources of information for all walks of fishkeeping!

Good luck, Linda, and take care.
Nicole