Hi there. Recently I was reading some stuffs about nitrates and phosphates and I found some scary informations on the manual of PO4 and NO3 kit tests. Just take a look:

This information is from 2 big brands, Sera and JBL. They don't say to keep NO3 and PO4 at 0 ppm but advise us to don't let the NO3 level to be above 50 ppm and PO4 above 1 ppm. According to both brands, these nutrients levels will induce algae blooms besides injures fishes and the own plants. To be clear, JBL recommends a NO3 level range between 10 and 30 ppm and a PO4 level range between 0,1 and 1,5 ppm. In the other hand, the brand Sera recommends to keep PO4 always less than 1 ppm and NO3 less than 50 ppm, preferably less than 25 ppm.
So, it's known that zero NO3 and PO4 causes algae, it's true. Because without them the plants become malnourished and weaken what makes algae boom. Fine, this makes sense. But what happens if we dose too much NO3 and PO4? Well, It seems to be harmful as well, leading the algae to bloom.
So my question is, should we dose less than standard EI? I was thinking to dose half of EI once a week. I mean, 1 ppm of PO4, 10 ppm of NO3, 2 ppm of Mg, 4 ppm of Ca and 0,2 ppm of Fe once a week, after water change, in a high light tank. What do you think about? Please, share your opinions. Thank you.


This information is from 2 big brands, Sera and JBL. They don't say to keep NO3 and PO4 at 0 ppm but advise us to don't let the NO3 level to be above 50 ppm and PO4 above 1 ppm. According to both brands, these nutrients levels will induce algae blooms besides injures fishes and the own plants. To be clear, JBL recommends a NO3 level range between 10 and 30 ppm and a PO4 level range between 0,1 and 1,5 ppm. In the other hand, the brand Sera recommends to keep PO4 always less than 1 ppm and NO3 less than 50 ppm, preferably less than 25 ppm.
So, it's known that zero NO3 and PO4 causes algae, it's true. Because without them the plants become malnourished and weaken what makes algae boom. Fine, this makes sense. But what happens if we dose too much NO3 and PO4? Well, It seems to be harmful as well, leading the algae to bloom.
So my question is, should we dose less than standard EI? I was thinking to dose half of EI once a week. I mean, 1 ppm of PO4, 10 ppm of NO3, 2 ppm of Mg, 4 ppm of Ca and 0,2 ppm of Fe once a week, after water change, in a high light tank. What do you think about? Please, share your opinions. Thank you.