Keeping the aquarium clean and smelling good!

We just added a couple goldfish to our tank about a week and a half ago and ever since it has really started to smell. We recently changed the filter as well but that smell does not seem to go away. It also is a bit cloudy in there. Any suggestions on what else I can do to make that smell go away and keep the water cleaner? None of the fish seem to be effected by it thankfully.

Hello Amy, you will need to provide more information for any of us to find the problem.

Your tank size?
How many fish? (what species? list them all if goldfish are not the only species)
What filter system?
How much and how often do you feed?
How often and how much water do you change as a part of regular maintenance?


Some things you need to know.
1. Goldfish require large tanks because not only they can become very big, they are also known for being messy.
They need minimal 20~40 gallon of water (each) depends on if they are fancy goldfish or common goldfish.
Undersized tank will always be messy no matter what you do.

2. Messy tank is also often a result of overfeeding. You don't need to feed more than once a day, and as much as the fish can finish within a minute. No leftover fish food should be visible in the tank, or you need to immediately remove them.

3. Filter or the filter media should not be replaced unless absolutely necessary. They also should not be washed under untreated tap water, because chloride will kill the good bacteria in the filter media necessary for the nitrogen cycle.

4. Weekly partial water change should be done along with vacuuming of the substrate as a part of the regular maintenance.