Ammonia levels and nitrogen cycle
I just started a new tank (5.5 gallon that I've had for years) with a new betta about 3 weeks ago. I've had multiple tanks, 38 gallon, 55 gallon, and a few betta tanks in the past. About a week in, he wasn't acting right so I checked the ammonia and it was super high. Since then, I have been doing multiple water changes a day, trying to get the ammonia levels down as well as always vacuuming the gravel when I do a water change and I feel him very little twice a day, which he always eats everything I give him. I can get them down but then they go right back up. I am currently trying to seed the tank from with filter media from my established 38 gallon but I don't see any progress yet. I've been keeping the ammonia levels below .5 pretty easy with water changes but it hasn't moved to the nitrite stage in the nitrogen cycle yet. My PH is usually between 6.8 and 7, it doesn't really change much. Ammonia is at about .25ppm right now, nitrites at 0ppm, nitrates at 0ppm and temperature is at 78 degrees Fahrenheit. He was super pale, lethargic, and sitting on the bottom of the tank, since I've gotten the ammonia down, he seems much happier and has gotten all of his color back. I'm just not sure how to get the ammonia levels all the way down and move the nitrogen cycle along. I've tried ammonia detoxifiers but have been very careful and only using them as a last resort. I've never had this much trouble with a tank before. Can anyone help?