HELP! Indoor Hemp chlorosis.

[TTT31]

Lumatek 600 Zeus pro on 50% PPFD 350 measured by Apogee Led optimized Par sesor
EC tap water 0,4
Ec Total with Canna terrra 1,1
Biobiz Light mix
Ph 6,3 then 5,8
Not over watered
room temperature 22-27 C
CO2 in room 500-600PPM
Strains under 0,3 THC european hemp
relative humidity 40-55%

Hi Guys, I never come across such chlorosis. All looks like Iron deficency treated with foliar spray Canna Fe also with Calmag different treatement tried on different plants. Some plants are month old some 14 days. After planting rooted plants and placed under the lights the new growth started yellowing. In two days obvious yellow. and keeps yellowing. We flushed some plants really a lot next friday and it did not help. What might be the cause of the problem? See pictures. Have anyone seen this in such scale? All plants affected...I never seen such thing over last 20 years. We also tested the tap water in lab.. I am pretty sure that our PH meters are alright cross tested with others... Is there anything special about Hemp cultivation compare to regular canabis strains? all new growth is yellow even the lower branches old leaves stay green. This is Iron deficency and chlorosis to me but do not know what could have caused it and how to fix it... It went too fast just transplanted watered and put under the lights. Nice green seedlings got yellow in several days

[Rwise]

Get the PH to 6.5 if this is soil. they are in lockout, iron or sulfur, 5.8 is to low for soils.

[9fingerleafs]

Are they in soil? 1.1 ec is low, it’s obviously lack of nutrients because the light cause them to grow faster than the nutrient intake. Don’t know what the solution might be. Not even sure if he problem is too low ec, too low ph, or could be a root issue, could be bugs, could be fungi, I don’t think it’s nutrient lock out so what you need are nutrients not flushes

[ChadWestport]

That looks like an iron deficiency.

Were they ever under the lights they were when they developed the problem?

Have you ever used those lights for plants of the same age before?

Were there any additives or supplements you added or forgot to add while transplanting?

[TTT31]

every cause eliminated by method of exclusion.... yesterday I found pictures on the internet looking same and the cause was Lino flooring offgassing... WE gonna replace ours today and will see.

[Rwise]

I'll be watching for the next pics!

[Scooter]

Ph is a little low but souldnt create the issue you have. Only on new growth? Micro nutrients may be issue but I would suggest Nitrogen deficiency. Are the plants growing quickly? Lights may also be to close. Look for signs of light burn. I agree flush is not the answer.

[gbauto]

I agree that this looks like an iron deficiency.
If you're confident about your nutrient mix, I would look at the possibility of an excess of antagonists to Fe.
Too much of any of Ca, Mn, Cu, P, and Zn can create an Fe uptake issue.
The ph you're running should be good for iron uptake.

[Richym]

My cheese looks yellow like that but it’s in the flower stage

[Kalebale]

I had this happen once, my problem was iron toxicity which locked out manganese. I flushed then potted up to a more neutral soil and added a grow nute mix. Fixed it 100% in a week.

[ChadWestport]

Its not uncommon that when one of the micronutrients is out of line, there are a couple others as well.