The N-P-K would naturally be relevant to the fish load and how long the tank has been setup.. By the time you tested it would be different again lol. My guess is that it'a about a third of the necessary nutrients for most plants. The great part is that it could never burn and all the elements are in a stable form. Certainly better than straight tap water,but wouldn't expect to quit fertilizing.
My orchids seem to do well with it and I only resort to chemicals about every two months.
A lot of tropical plants can be grown permanently with the floating method. Be sure to remove all the soil and keep the leaves out of the water.
Introduction to Fertilizing the Planted Tank - Aquarium Advice
Fertilizer requirements depend on what you are growing, how fast plants are growing, and your stocking level. In a lightly planted tank with several fish, good feeding, and hardy, slow-growing plants, the need for additional fertilizers is probably nil. For large, root-heavy feeders (such as Amazon swords), it may help to add fertilizer balls or root tabs to the substrate. If you have filled your tank with plants that grow fast, have some aerial roots, are epiphytic (plants that attach to surfaces and are not planted) or float, and your stocking is light to moderate, then liquid or powdered fertilizers may be of assistance.
Fertilizing aquarium plants | Algone
By the way, even tap water contains soluble iron, but in the high oxygen environment of your aquarium it quickly turns to rust which the plants cannot use. Chelated iron doesn’t oxidize quickly and so will remain available for weeks. Also try the Osmocote tablets described below, which are in all respects identical to the pond lily tablets. In summary, I would add some solid nitrogen containing fertilizer in the substrate (especially Lilipons or similar initially at 5 grams per 10 gallons), check for high nitrates (if they’re high (above 10 ppm), stop fertilizing with nitrogen and increase water changes until they lower), and add chelated iron (especially if the plants take a turn for the worse). Note that the proper levels of fertilizer will depend on fish load, water chemistry, and water change frequency, so you will have to watch for the needs of the tank.
Best Aquarium Plant Food for Strong Plant Growth - Organic Lesson