a bad smell coming from fish tank

I just a koi fish and a 3 gal tank and now the water has a bad smell to it. i added clear water treatment to it today but it said on bottle that it would take up to 48 hours to become clear.Should have I gotten the tablets form of clear water instantly??

i think you feed that koi too much,the bad smell in my opinion is for the unwanted toxic ammonia and nitrite level,if you test the ammonia and nitrite level i am sure that it must be high..so do 40 % water change daily so that these toxic substrate cann't form..

i was thinking it was me feeding my koi too much but i did change all the water earlier tonight and it smells alot better. So how many times should i feed my koi??About how many small pellets each feeding??I notice some pellets get stuck on the filter so i watch and the koi does eat them in some time and then i notice all the pellets are gone so i give more and he chos down but not alot.He is swiming up and down along the side in one spot is that ok??thanks for ur help.please reply again quick.

hm so it is due to over feeding.. usually you should give 2 times a day,but also keep in mind that you should not give him over feed,because you said that the extra pellets go to the filter....and the extra food the koi cann't eat go down and cause ammnoa and nitrite level high..since you have a small 3 gal tank,you should care the tank in proper way.feed them twice but not over feeding..you may give him 10 pellets..feed in the morning and in the evening..

The partial water changes suggested by helinova will help the aquarium much more than any chemical treatment. Just use a good water conditioner for the replacement water, and feed no more than the fish eats in a couple of minutes.