Tank water is cloudy and smells

Question
A mate has leant me his old fish tank. The tank is hexangnul and is 30cm diametre and 45cm in height and has a filter. I filled it up on Friday and put two goldfish in on Sunday. By Monday evening, the tank had become cloudy and the water had started to smell. What is wrong and how can I rectify the problem?

Thanks

Lottie

Answer
Hi Lottie,
Definitely a water pollution problem here! Quite obvious!

This is because the tank hasn't had a chance for the good bacteria to establish and control the ammonia/nutrients that fish produce. So when fish are added to a new tank setup, the water gets dirty very fast and their is a bacterial explosion as a result.

The smell is likely ammonia. Which is very deadly to fish, it burns their gills, skin and fins.

Immediately change 50-75% of the water (make sure replacement water is treated with a water conditioner and the temp is equal to the temp of your tank or just a bit warmer)...you may have to repeat these water changes until the problem is resolved. The ammonia may be so built up it takes more than one water change to dilute it down.

Your tank needs time to cycle. And it would help if you had test kits for ammonia, nitrite, and nitrate. This is so you can monitor your water quality and the cycling process.

Your tank may need several weeks to establish and settle. Patience and water changes are key here.

I hope this helps and best of luck!
Karen~