Hi,
I guess there may be several issues with the use of test kit from a beginners standpoint. Each issue is a double edged sword though, and which edge you get depends on the person using the kit. There are educational, practical and perhaps psychological issues.
From an educational standpoint I suppose it's a good idea for a beginner to be introduced to the basic parameters of water chemistry such as hardness and pH. This much is clear. But what does the person actually do with this information? It depends on how much he/she is willing to read and research in order to gain a better handle on when to worry and when not to worry. How many times have we seen a question raised where a beginner is concerned his/her pH is not what was expected, or that it changed during the day? How many products are sold on the market that profess to "correct" pH? pH buffers abound and they are all completely useless, yet, we see many beginners buy a pH kit, measure pH, decide the number is not good and then proceeds to buy pH down and to dump sulphuric acid into the tank in an attempt to manage pH? If a beginner does not understand the relevance or ramifications of a parameter is it value added to even measure it? We know that pH is not an important parameter for the typical community tank and that high pH or low pH is only a concern for specific niche species. I would be willing to bet that a large percentage of beginner plant enthusiasts are unaware that their CO2 test is actually a pH test. I feel it would be better for a beginner to not start out with a pH kit, learn about the characteristics of pH through reading and research, and then, if there was some specific goal or objective to determine ph, then go out and buy the kit now having gained insight as to what relevance it has.
Lets look at a nitrite (NO2) test kit. At what time, other than tank startup, would you ever see a non-zero reading for NO2? If a beginner is taught about the nitrogen cycle then he/she will know to expect an NO2 rise and fall. It may be fascinating and illustrative to do a test to see what the NO2 level is, but after that? I still have an NO2 reagent bottle from 10 years ago. Would it not have been better to simply know that the NO2 concentration buildup is inevitable and that it passes after a few weeks. Would in not be better to simply advise a beginner to not stock fish for at least several weeks? NO2 is completely irrelevant for plants so when would we ever need to test for this parameter?
NH4/NH3? Similar story. NH4 test returns a positive result during tank startup. After that it would only yield a positive result if general tank maintenance was exceedingly poor. If the beginner fails to comply with standard tank maintenance procedures and fish die as a result, isn't it a safe conclusion that the fish died of ammonia poisoning? Would you have needed to test? Water pollution kills fish. End of analysis.
NH4 levels that cause algae are read as zero on an NH4 test kit so this kit does nothing to help grow better plants. Better to learn about NH4 implications instead of measuring it.
KH/GH? Again, nice to know but how does this help you to grow better plants? How many beginners actually even know what these parameters are and what they mean with respect to plants unless they did some heavy research? I'm sure someone will know if they live in a hard water district. You don't need a test kit for that. Will your procedures differ significantly if you have GH10 versus GH17? Probably not. Again, these are parameters that are best measured
after someone has gained knowledge about their ramifications.
NO3/PO4 - how many beginners are under the impression that NO3/PO4 causes algae? My guess is 100%. How many experienced aquarists who are plant beginners think that dosing NO3 is a bad idea? My guess is 100%. If a beginner thinks this and buys the kit and measures the values, then 100% of the time they will panic at the high values. Since many are seeing algae at the same time this reinforces the fantasy. In my opinion it would be better to have the beginner not buy these kits, unlearn the propaganda of nutrient/algae relationship first and then if necessary go test for nitrates/phosphates. They will then understand the ramifications of what they are measuring. SuperColey1 makes an excellent point here. Look at your tank with your eyes. Can you see BGA? What special knowledge or experience is needed here? If you see BGA then you need to dose more NO3. Who cares what the test kit says? Can you see BBA? Yes, it's black and looks like a brush. If you can see it you need to fix your CO2. No test kit required for this.
In my opinion therefore the situation is completely reversed. Test kits do nothing for beginners except foster paranoia and misinformation. Yes there may be some comfort in having a kit but the kit doesn't save you. There are thousands of people using kits who haven't figure out how to solve the problems they are measuring for. On the contrary, I feel one should get test kits
after one has experience, not before. To me a beginner with a test kit is more akin to being issued a drivers licenses before being issued a learners permit.
Cheers,