Too little info to help: 1. what is ph?, 2. what is water source? 3. what was your process for adding fish, 4. how did you treat your water, with what and how much, 5. what are your water test results?, 6. what was your source of fish, i.e., how know healthy. 7. what was temp of tank and fish container when added. Is this the only breed you have difficulty with? 8. when change the water, why so frequent, and how much of volume are you changing.
that should be enought to get you started
that should be enought to get you started