PPM, PH and nute chart...help

Hi
I am in my second week of my first aeroponic grow in a grow box. Did a lot in soil outside but life takes you elsewhere and you change grow style. I follow the GHE chart and after adding the nutrients my PPM is 250 and in 2/3 days drops to 80. Isn't that low?
The other annoyance is the PH because it rises from 5.8 to 8 in 3 days. Is this normal? The roots are looking good, some are just a little red/brown, doesn't look like root more likely because of hydroton.
Thanks in advance

That PPM is very low. If the plants are in later veg or flower your PPM should be closer to the 800+ range (on the 500 scale). What is the PPM of your plain water and what stage of growth are you in? You can easily keep the same ratio of GHE and just scale up, I would look to double up or even triple up your nute levels

Thanks for your answer mjinc. I am in my second week of veg, the plants are growing their third pair of leaves. My tap water PPM is 120. The GHE chart says 2.5ml per 10 litres; I have a 30 litres tank so I used 7.5ml but the PPM is still low when it should be about 400. I will try to double or even triple up the dose and see what happens.

eiht98 said:

Thanks for your answer mjinc. I am in my second week of veg, the plants are growing their third pair of leaves. My tap water PPM is 120. The GHE chart says 2.5ml per 10 litres; I have a 30 litres tank so I used 7.5ml but the PPM is still low when it should be about 400. I will try to double or even triple up the dose and see what happens.

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Those are very low recommendations from GHE. I'm pretty sure that the GH formula from the US is the same as the one in Europe but the US recommended formula is two and half times what you're getting from the European site. I've included the GH feeding schedule link below but it's just a recommendation. My best advise is to start there and slowly play with it according to what your plants tell you. If you find they are drinking a lot up the dosage maybe 10-20%, or if your getting some nute burn flush with a weak nutrient solution then reduce the recommended feed by 10-20%.
http://gh.growgh.com/docs/Feedcharts/GH_FloraSeries-DTW_03216am.pdf

Thanks a lot mjinc, appreciate your help.

eiht98 said:

Hi
I am in my second week of my first aeroponic grow in a grow box. Did a lot in soil outside but life takes you elsewhere and you change grow style. I follow the GHE chart and after adding the nutrients my PPM is 250 and in 2/3 days drops to 80. Isn't that low?
The other annoyance is the PH because it rises from 5.8 to 8 in 3 days. Is this normal? The roots are looking good, some are just a little red/brown, doesn't look like root more likely because of hydroton.
Thanks in advance

Click to expand...

Your pH is rising because the plant is using up all the acids in the nutrient solution. This is normal, but damn she's a hog lol. I would try mixing her drinks a little stiffer.
Good luck and
Keep on growing.