Hi......I have a 10 gallon tank and yesterday I did a half water change in it......since I had to add gravel. I also added an air stone with sponge filter to make bubbles. My tank is nice and clear...but today I notice it has a urine smell to it. I've never had that problem before. Does anyone have any idea why?

Thanks

I need some more info.

How long has this tank been up?
What is the filter on the tank?
HOw many fish in the tank?

What kind of water conditioners do you use?

Most of all what is your Ammonia, nitrite readings?

I'm new at owning an aquarium..maybe a month now........it's a 10 gallon tank with a guess you call it a power filter that has a blue filter pad with charcoal in it. The whole month I've had my aquarium, I haven't had any problem. It's not until yesterday when I changed half the water and added the gravel and airstone/sponge filter. I had a fan tail goldfish, a siamese betta, a little zebra fish, a small dannio and a small placo. As far as water conditioners, I've never used any except for Ammonia Chloramine Eliminator yesterday since I did a water change. I don't know what my ammonia reading is......hmmmm....I'm just a beginner.

Okay to help you can either go to the local fish store with a sample of your water and they will test the water for you. Ask them for the number readings. Testing your water at any stage of fish keeping is the only way to find out if its a water quality issue or not and ammonia and nitrites can kill. Ammonia is what your most likely smelling and with out a proper reading I can only guess.

Since your tank is new when you did a massive water change it most likely made you start a minny Cycleing over again.
When you get the chance look at the top if this board you will see a link to Cycling of tanks this will help you understand what is going on in a newly set up tank:D

IM really sorry about this off topic thing but
koko your on and i don't see your name on the bottom of the main message
board page

Thanks! I cannot go to our local pet store for a few days....what should I do in the meantime? Should I do a partial water change every day? 10% or so?

Just do 10% dont do a gravel siphon on the gravel....