Help! Whitening of leaves overnight

[RachelLuli]

First time caretaker grower, & I'm in the 5th week of vegetation. I've had many, many issues with PH balance which has stunted the growth.

FYI -

aeroponic system
20 gallon
soilless
15 min on / 15 min off water pumping into root system
18 hrs flourescent lighting 6 hours darkness
good humidity

Last week I changed from general hydroponics to Cyco nutrients. I used their kleanse solution for 2 days, ph balance was good. two days ago I reloaded the 20 gallon tank with cyco nutrients including their dr repair solution.

Yesterday, I noticed such a rapid growth, almost like 2 inches per plant. This morning, I found white-ish discoloration on the lower leaves of the plants. There was also curling at the ends both inward & outward.

PH level was EXTREMELY LOW, at 4.5. Yesterday when I checked the PH it was at 7.5 so I regulated it with ph down solution.

I spent the day researching and it could be a combo, low ph preventing nutrients from absorbing, so new growth is depleting the nutrients from the lower leaves?

Could be -
Magnesium deficiency
calcium deficiency
nitrogen deficiency

I've now managed to get the ph in the 5.5 to 6.5 ratio. I also moved the flourescent lights 6 inches further away, they might have been too close?

Can you expert growers please help! What are your thoughts?

I have pictures however I couldn't figure out how to post them on here! ;(

Thank you!!!

 

[aperson]

Photo Gallery Guide - How to Resize, Upload & Post Photos

All I can do for you friend!

 

[RachelLuli]

THANK YOU SO MUCH! Uploading them now!

 

[RachelLuli]

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[Emilya Green]

starting at the bottom and rapidly moving up... looks like a macronutrient deficiency... your plant cant get nitrogen! That is actually pretty hard to do... get that pH in line quickly.

 

[RachelLuli]

Should I flush the entire 20 gal nutrient tank right now? PH is back at 5.5 now. leaves are very limp.

starting at the bottom and rapidly moving up... looks like a macronutrient deficiency... your plant cant get nitrogen! That is actually pretty hard to do... get that pH in line quickly.

 

[Emilya Green]

Should I flush the entire 20 gal nutrient tank right now? PH is back at 5.5 now. leaves are very limp.

I can't really answer that, not being a hydro girl. If the stuff is in there though, I would think it would be ok as long as the pH is where it needs to be. You are the boss though... only you can make all the hard decisions, since it is you standing there.

 

[rillos]

Where are you getting your water. In hydro using anything other than RO/distilled water will screw your with your PH just like you are having with it dropping down fast and hard.

 

[RachelLuli]

Where are you getting your water. In hydro using anything other than RO/distilled water will screw your with your PH just like you are having with it dropping down fast and hard.

Absolutely. I am using distilled water. Right now the ph has been at 5.5 for most of the afternoon. The leaves still look very sad. Tops of the plants are looking good, I'm almost temped to take the tops as clones with rooting hormone, at least to save part of the plant....

I will take pictures in the morning & post to see if there are any changes....

 

[rillos]

I grow in a DWCR system 2 19 gallon tubs and I use the GH nutes so i'm just wondering why you switched. I've never really heard of those other nutes.

 

[Atulip]

Haven't seen white like that before, but the pattern is identical to Magnesium deficiency. Starts at bottom leaves and moves upwards, losing color with the veins remaining green. They look very droopy also, are your roots healthy and getting enough oxygen.



Mg deficiency.