Thats why I am using 2 different testing methods, one professional drop testing kit and strip tests (untrustworthy).I think its possible, others may disagree. A lot of people on the forum dont trust test kits much, I am starting to trust them less and less myself. Your tank has only been running a month though, so quite a short time, things may change later on as everything settles down.
I think adding small amounts of fertilizer often will be better for your system than adding a lot more rarely. Algae have evolved to thrive with rapid changes, while plants are slower but can tolerate bad periods better and store nutrients because of their complex structures. Plants slowly (week or more) adapt to the conditions they find themselves living in, therefore it is almost always a good idea to keep things as stable as possible. Otherwise they spend a lot of energy trying to reprogram / readapt themselves all the time.
I will simple do regular once a week dosage but maybe half the recommended dosage to see how my plants respond. Every plant (but two) is growing really well. I am struggling really hard with Montecarlo and Hairgrass, thats why I bought a Co2 system in hopes that it will make it possible to grow some carpet.