You will not see a different reading if you haven't addressed the source of the Ammonia. It will be the same. However while your sorting your problem out if you stop dosing prime the Ammonia will become toxic and become harmful to your fish.
Get extra filtration or media in the form of what ever you want. Add some sand, it's not the worst thing in the world and can be vacuumed up later. Get more sponge filters and hook them up. Or buy a few large lava rocks and place them in the middle of the tank as a center piece. Get Dr Tims or Micro Bacter. Dose it on your media. Keep dosing prime and only change enough water to keep your Ammonia at 2ppm. It's possible that your filters not building because by doing water changes to reduce the Ammonia your reducing your filters food source. So In doing that your preventing your biological bacterial colony from growing large enough to handle the bio load. You have to ride the cycle out. Even though it wasn't your plan, your doing a fish in cycle right now. However you got here who knows. It just happened to me on an established tank with cherry shrimp.
I handled my problem by doing this.
Adding extra media to my tank from other established tanks.
Dosing prime daily to detox the Ammonia and keep my pets safe during the re cycle process.
STOP doing large water changes, or water changes at all because your taking away your filters food source so it won't grow and you will be stuck in water change/ Ammonia spike stage forever.
Does a high quality nitrifying bacteria additives like Dr tims.
If you buy some sponge pages on Amazon. Or local fish shop. Lay them on the aqurium floor (cut to size) seed it with Dr Tims or micro bacter. You then have a temporary substrate. Once the tank is established you could slowly remove it.
In short, it's my opinion that you need to
Dose prime every 24 hours to keep your fish safe ( detox your Ammonia)
Add more surface area to seed with bacteria untill the tank is established.
Seed that surface area properly by turning the filters and power heads off and allowing the bacteria to colonize.
Keep your Ammonia level around 2ppm until it drops below 2ppm with out a water change.
If you can afford it, buy some purigen and put it in the canister to help handle the bioload while re cycling.
Of you have sponges or bio medua from another tank you can afford to use toss them in the tank.
When my shrimp tank did this and I realized what was happening, the first thing I did was double dosed prime daily and stop water changes. That was a bandaid. I then addressed the problem.
Bare bottom tanks are fantastic when they work. This one is not working right now you have to do somthing different. Try laying filter foam on the tank floor and seeding it. You already have filtration, it sounds like you need more surface area.
Or, Stop doing water changes triple dose prime as per the recommendation for aqurium upsets and let your filter grow. I'm sure there are numerous ways you can attack this. In any scenario though, like your fish if you take away food ( ammonia) from your filter it will not grow