Hi, I have a fantail in my 2.5 gallon aquarium. I read the cycle of the tank part on this forum but I still have questions.
1) I just read that you aren't suppose to do gravel vacuuming while cycling the tank. Is this true? because I have been doing it all these time while changing the water.
2) I ran a couple of tests: Ammonia & Nitrites. Both level are high. Is this normal. If both of these are high, I was told that I can control this by doing small water changes.. but how often? Daily? I checked my aquarium daily and the result is the same. I changed 10-20% of the water daily. Is this the correct way to do it?
Thanks for your help!!

Honestly trying to cycle that small of a tank is going to be hard, plus the goldfish is going to grow fast and it will need a minimum of 10 gals per goldfish.

When your cycling you don't want to gravel siphon cause this is were the good bugs live, once the tank is cycled you can do it cause there is enough bugs to keep it going when you take out the gunk off of it.

When you say high how high is it?

Anything above the 1.00 mark of both is very deadly to fish. Doing a 10-20% water change is good daily, this will help keep it down.....

when your cycling your tank, the amonia will be high in the beginning - this is normal. Then the nitrites will be high - this is caused by the bacteria that live off of the amonia and it is also normal. The amonia will start to drop slowly - water changes will help but you shouldn't have a load of fishes in the tank anyway at this point. Lastly, nitrates will develop. This is caused by the bacteria that eat the nitrites. Amonia levels should level off at a very low amount, the nitrites should level off at a low amount and all that should remain are the nitrates which will be taken care of by water changes and algea.

OK. I'll try to change the water daily and perform the test daily to monitor the level. Thanks for all the suggestions! Really appreciate it

Now my ammonia is down to 0 and I have very high nitrites. I should expect this to happn, right? How often should I change the water again in order for it to not kill my fish?

i would change 30% of the water daily to help out with the fish.

My 2.5 gallon betta tank is cycled, though how steady that cycle will stay I can't say for sure yet, and the bioload is much lighter than having a goldfish. Even with only changing the water about once a week during cycling the levels did not go over 1.

I would really try to change the goldfish to another tank.