Hi,
I use CES (Cutting Edge) nutrients. Similar to GH. I've never checked PPM before because I've never had a PPM meter. With over 10 years experience, I've had only 2 poor crops and neither were due to nutrient deficiency.
Anyway, I started monitoring and I see a beginning PPM with fresh reservoir of nutes at 1140. This includes the 150 that the water comes with before adding nutes. After 5 days it's at 800. It seems to be going down between 50 and 100 PPM per day. I usually change my res at around 10 days. In which case I'll probably be down at around 450 - which seems very very low.
That's actually not my issue/question. I've ready many times through this forum and other forums that you should monitor PPM and add nutes when it goes down. This makes no sense to me. PPM is a measurement of ALL nutrients and anything else in there. So, let's say your nutrients go down 400 PPM. What if this reduction is in the amount of potasium, magnesium, manganese, and phosphorus. And the nitrogen hasn't depleated at all. If you increase the whole nutrients by 400 PPM, wouldn't you be risking nute burn with the nitrogen? That's just an example.... I'm just saying that PPM isn't going to tell you what nutrients are being depleted and thus is riskier to add nutrients than to wait and change the reservoir.
If someone has an argument to that, I'm willing to listen. Since I'm not a full on botanist, I don't know exactly how plants are taking in the nutrients. Maybe they take them all in equally or something that I don't realize while theorizing here.
I use CES (Cutting Edge) nutrients. Similar to GH. I've never checked PPM before because I've never had a PPM meter. With over 10 years experience, I've had only 2 poor crops and neither were due to nutrient deficiency.
Anyway, I started monitoring and I see a beginning PPM with fresh reservoir of nutes at 1140. This includes the 150 that the water comes with before adding nutes. After 5 days it's at 800. It seems to be going down between 50 and 100 PPM per day. I usually change my res at around 10 days. In which case I'll probably be down at around 450 - which seems very very low.
That's actually not my issue/question. I've ready many times through this forum and other forums that you should monitor PPM and add nutes when it goes down. This makes no sense to me. PPM is a measurement of ALL nutrients and anything else in there. So, let's say your nutrients go down 400 PPM. What if this reduction is in the amount of potasium, magnesium, manganese, and phosphorus. And the nitrogen hasn't depleated at all. If you increase the whole nutrients by 400 PPM, wouldn't you be risking nute burn with the nitrogen? That's just an example.... I'm just saying that PPM isn't going to tell you what nutrients are being depleted and thus is riskier to add nutrients than to wait and change the reservoir.
If someone has an argument to that, I'm willing to listen. Since I'm not a full on botanist, I don't know exactly how plants are taking in the nutrients. Maybe they take them all in equally or something that I don't realize while theorizing here.
