Hi txice,
The good news first: plants not only seem- but actually are very adaptable to their environment and hence to the
nutrient strength and composition you feed. In nature they need to adopt to different conditions as well. But that also makes it difficult to optimize hydroponic nutrition at a second level.
Advice for your particular case now: don't cut back the concentration radically, because on the other hand sudden and big changes is what plants take less well. As they (actually mostly) don't occur in nature.
The bad news: understanding formulas and nutrient composition is not easy in the beginning as there is very
specific knowledge and understanding required, before it makes sense. Furthermore there are many misconceptions, actually due to the fact that people tend to simplify things for a better understanding. They also tend to do a lot of cherry picking that is linked to their own experiences and personal situation. All of it is quite understandable, but in many cases it's not exactly objective nor good enough for a general role.
The other problem is, that in most cases you can't give real good advice without rather extensive explanations. If you don't attach those, people won't understand the "why" part of it, and simply switch back to their own understanding of things, or go for the often primary information they grab from any website. If you overdo the explanation part, you scare people back in their misconceptions
And the real bad news: with any commercial
nutrients, the possibilities of adaptation and balancing are always limited. You have to trust them, without actually knowing what you are doing.
My set of advices keeps the same:
1. for tomato use a
tomato formula that is supposed to have low nitrogen and high potassium content, rather rich in magnesium and calcium.
2. Don't cut back nutrient strenght to 1/4 and not even to half. If you cut it back now, just cut back to about 75% of what you have now.
3. On a second level of understanding: the key element of any nutrient formula is not the total concentration, but the content (the amount) of single elements in the formula (as in NPK, Mg, Ca, S, etc.). It's the content of
each element that makes the total of the nutrient strength, not the other way round. Using only the concentration as a variable (without knowing the composition) is indeed like tuning an unknown. The specs of any formula are in the composition- and if you change the concentration of your formula to a certain extend, (wether higher or lower) it obviously gets imbalanced and inadequate.
4. Hence diluting any formula (as in any commercial product) to a quarter of their initial strength, means screwing it all up and creating a perfect imbalance. If needed I can give an example of what actually happens to a typical nutrient formula, as soon as you leave the limits of it's initial concentration. In figures it makes a lot more sense.
5. Three main issues come with commercial products:
A. The manufacturers need to conceive their product in a way they can keep instructions as simple as possible. Because that way they can sell to a wider range of customers.
B. They don't want to reveal any of their professional secrets.
C. Hence they won't teach you anything (or as little as possible) as they know that the best customer is an ignorant customer.