My Aquarium
You might still find yourself, even after learning what you have learned, wondering whether or not you should look further into the purchase of some of the many chemicals that are sold for fish. After all, there have probably been a few people that told you that there is an obvious benefit to the fish or else this stuff would not be sold. Obviously, there could not just be a company trying to make money off people willing to buy into anything. But, you still think that some of these chemicals might be needed. Before you purchase and start using anything, you are going to want to make sure that you are asking yourself a few questions. If you can't answer these questions, you might want to rethink the purchase of such chemicals.
For starters, do you know why in particular you are adding these chemicals? Basically, what are they doing for the aquarium, for the fish and for you? Who is benefiting here? Are there many side effects that can be expected or should be looked for when using such chemicals? What are you going to do if you find that the chemicals you purchased for an all-important reason, do not actually do the job that they claim they can do?
Another thing to think about is whether the chemical that you will be using will have any bad interactions with other chemicals that you are using in the aquarium. If there are no bad reactions, how do you know if the chemical actually did anything at all? Are you going to be left just assuming that it worked? If the chemical does alter the aquarium, but a little too much, is there a way to correct this? Could your fish die from too much of this chemical? If so, just how much is too much?
What about the filtration? Will the chemicals that you are looking into buying affect the filtration any now or in the future? Also, if the chemical you are being sold is meant to correct something, how are you to know that this "something" is actually wrong in your aquarium or are you just guessing?
If you find that after careful thinking you are not able to properly answer all of these questions, you should not be trying to add chemicals to your aquarium that do not need to be there. Even if your aquarium did need something, which it probably doesn't, you need to make sure that you have as much information as possible in order to properly do the job. Otherwise, you are simply going to want to make sure that you are leaving the aquarium alone.