When you say you are making your own water instead of using pre-made, what are you doing to make your own water? Are you using RO/DI water or water from the tap? Using salt mixtures per directions of the box?
When you say ammonia is the only thing that is high, what parameters are you checking? With an increase in ammonia, you should being seeing nitrites increasing within 24-48 hours. I recommend testing ammonia and nitrites daily. Since you have fish in the tank, you will need to be on top of this. Do water changes if you detect any level of ammonia or nitrites. This process is going to stress your fish in the tank.
How long has the tank been set up? You mentioned "just started", does this mean the tank has been set up for a week? Greg provided a great chart to help identify when your tank has cycled and the first fish can be added. How long did you give the rock and sand time to cycle before adding fish? You added 4 fish to a 25 gal tank. What was the timeline of adding those fish? All within the same day/week?
A 25 gal system will be more succeptable to water parameter changes than a large volume tank. Adding one fish will greatly increase the bioload of a 25 gal tank than it would on a 250 gal tank. The amount of bioload increase is the same, but the impact is greater on smaller tanks. Time is needed for your tank, bacteria, and husbandry skills to adjust to the new bioload. Recommendations on this are approximately one fish per month. Some of the larger tanks can get away with two-three, but your tank will have a greater response.
At this point in the game either remove the fish and let the tank cycle or stay constantly on top of it. Your clown is demonstrating stressed behavior patterns most likely due to your water. Not that you are using the wrong type of water, but that your system hasn't cycled enough for the bacteria to break down fish and food waste.
With the frequent water changes, also keep an eye on salinity. Evaporated water needs to be replaced with nonsalt water since the salt doesn't leave the tank. For people who do weekly water changes, a recommended approach is to top off the tank with clean water first and then do a water change with salt water (or continuously top off the water with an automatic system). For those who do daily water changes, salinity may get out of whack due to not accounting for evaporation.
A common mantra in the hobby is "nothing good happens quickly in a tank". Don't let the loss of your first clown discourage you.