advice needed

[Kevthe1st]

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Attachment 289081
Attachment 289080

[Kevthe1st]

hi guys
well this problem seems is pesistant
altho the new groth looks nice and healthy the leafs below turn a yellow then dry out also have brown discolouration on a few top leaf ??
these were grown from seed aprox 7 weeks now.

temp lights on is around 80
humidity lights on is around 40%
i have theses on 15 min feeds 3 times a day lights on the pots are always moist.

iv just changed feed to original hydro/a/b 37ml per 15 ltrs of each. is there anything i could add to remady this prob??
il post new pics shortly

[Kevthe1st]

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[bitemybud]

Best I can tell from the piks, It appears to me that you are over watering. Also; you need a ppm/tds pen. I would make nutrients 800ppm now that they are established, but you need a pen to make the nutrient strength adjustments.

Good Luck, Hang in there