Hi,
Well I totally understand why you feel the way that you do. Believe me, it's not my intent to bash you. I know exactly how you feel. I used to feel that way myself, until I realized the truth. In fact people find more problems than they solve using the kits. Problems that they can avoid simply by following some basic procedures.
As I continually try to point out, there are two major problems with hobby grade test kits. The first problem is a strong optical illusion and the second problem is that of misinterpretation of basic chemical principles. Because human beings are susceptible to illusions we fall prey to the test kit results, and because the wordd "chemistry" is a four letter word for most folks we assiduously avoid the discipline of studying and trying to understand the fundamental principles to enable us to properly interpret test kit readings.
In general, these kits are only able to register the existance of the chemical they are supposed to measure. They are not capable of returning accurate numbers, and they are not able to consistently register the value. That means they will return different values for the same concentration level, so you can never tell what the real number is. The worst kits of all are any kits that are supposed to measure any Nitrogen compound. That means NH3, NO2 and NO3 test kits are the least accurate and most inconsistent kits of all. PO4 test kits are about as bad. So there is the illusion. The numbers that you read are always in question. They can be hundreds or even thousands of percentage points in error. This means they are completely useless.
Secondly, inexperienced hobbyists really have no idea, for example what it means to have a PO4 of "XX" ppm. They usually get advice from the same lame LFS that told them it's OK to put fish in the tank the same day as it's set up. So the advice about what to do when a reading is high, is usually to buy some other product that is just as worthless as the test kits they were just sold.
Lets look at the alternative approach, which not only guarantees success, but also does not require the need to spend more money:
When you start a tank the reason the ammonia levels rise is because of the lack of bactria in the sediment and in the filter media. It takes 6-8 weeks for the population and diversity of life forms in the sediment to mature. It doesn't matter whether you use acceleration products or if you use nothing at all. No product can accellerate the maturity of the tank. Until such time as the population levels and the demographics of the sediment/filter microbes reach a certain level, the tank will always be susceptible to problems because there are not enough germs to do the job.
Just about every living thing excretes ammonia as a waste product. Ammonia is a byproduct of biological breakdown, so it's a certainty that NH3 will be dumped into the tank over time. We don't need a test kit to tell us that. In order to keep the concentration low, all we have to do is to perform regular and frequent massive water changes. This can be done daily or even 3X per week. The more water that is removed, the more NH3 is removed. So it's very easy to control the toxicity level in the tank. The factthat the OP already has fish in the tank makes it even more important to do frequent water changes and not wait for some test kit readings. The microbes in the sediment and in the filter bed will continue to grow and to multiply. After about 6 or 8 weeks the populations will stabilize and the tank can be considered to be mature. Fish can be added and the NH3 that they produce will be removed. This is automatic and is a guarantee.
If the tank has plants then this is even better. As long as the plants are healthy the plants will absorb the ammonia because this is a highly nutritious food source. So healthy plants remove the toxicity from the tank. You never need anything else. You never need to put ammonia or anything else in the tank. The higher your plant mass the more ammonia is removed. So we should be telling the OP to spend his money on more plants, NOT more useless test kits. Even plants that he may not intend to use in his aquascape can be used. Egeria, Elode and other fast growing stem plants such as Hygrophyla and Ludwigia should be planted. Lots of them, because they will control the NH3.
Not only do plants control the NH3 but they also provide an even more important service, and that is they release Oxygen into the water column as well as into the sediment. People don't realize how important this function is. They seem to think that the bacteria only need NH3 but that is untrue. Bacteria require Oxygen, PO4, Iron, other trace elements as well as carbohydrates. Dosing the tank with nutrients provides the NPK and trace elements condusive to bacterial growth. The plants will also release sugars and other carbohydrates for the bacteria to feed on.
So if we focus on having as many plants as possible right from the start, and if we keep the discipline to change the water and to keep the tank clean, we will find that both plants and animals will be healthy and there will never be a need to use a test kit. If we wait the prescribed period before adding fauna to the tank we will assure ourselves that the tank will be in a much better position to accept and assimilate the new inhabitants.
Test kits do not help you to do this, they only provide an illusion that they do. These are the key points to a successful startup, and this is the discipline that will help to keep the fish alive.
Cheers,