Week 8 having yellow leaves on plant

Hello,

I am seeing yellow leaves on my plant, what could cause this problem ? Is this minor or must I take action ? Like cutting them off or maybe some problems with under or over watering ?


Some details ; Week 8

Strain : THINK DIFFERENT AUTO
600 Watts Led Grow Light
Custom 60cm x 60cm grow box
water PH is Between 5.5 - 6
mix of 60 % compost 20 % perlite 20% coco peat
No ready made nutes available , using homemade alternatives
12 cm extractor

dont cut them off.

what nutrients are you feeding? what medium are they in?

They are in a mix of 60 % compost 20 % perlite 20% coco peat

For nutrients I don't have same access as for wast majority of people (homemade nutes here).

Water PH is at 5.5-6.7 range don't know exactly.

rodaol78 said:

They are in a mix of 60 % compost 20 % perlite 20% coco peat

For nutrients I don't have same access as for wast majority of people (homemade nutes here).

Water PH is at 5.5-6.7 range don't know exactly.

Click to expand...

well given your resources i'd say you're doing a very good job. the plants don't look bad don't do anything drastic. did you mix the soil yourself? a pH buffer like dolomite lime or oystershell lime would help to keep pH in range and prevent lockout. could also be caused by overwatering.

rodaol78 said:

Hello,

I am seeing yellow leaves on my plant, what could cause this problem ? Is this minor or must I take action ? Like cutting them off or maybe some problems with under or over watering ?


Some details ; Week 8

Strain : THINK DIFFERENT AUTO
600 Watts Led Grow Light
Custom 60cm x 60cm grow box
water PH is Between 5.5 - 6
mix of 60 % compost 20 % perlite 20% coco peat
No ready made nutes available , using homemade alternatives
12 cm extractor

Click to expand...

Back off with the light. To at least 22".

pulpoinspace said:

well given your resources i'd say you're doing a very good job. the plants don't look bad don't do anything drastic. did you mix the soil yourself? a pH buffer like dolomite lime or oystershell lime would help to keep pH in range and prevent lockout. could also be caused by overwatering.

Click to expand...

Yes made the soil myself , well in my country dolomite lime or oystershell lime are not readily available I will try to find some alternatives that suits, also watering twice a week , maybe cut that down also ?

hotrodharley said:

Back off with the light. To at least 22".

Click to expand...

Great! will try that also and see if there are improvements

Also for Dolomite lime , what is the quantity needed for one plant ? Mix it in soil or in our water ?

rodaol78 said:

Also for Dolomite lime , what is the quantity needed for one plant ? Mix it in soil or in our water ?

Click to expand...

soil. i dont make my own soils i buy soil that has lime in it already. i am no expert. but i found this

https://www.harrells.com/blog/im-lime

"In potting soils, most foliage and flowering plants prefer a pH in the 6.0-6.5 range. To accomplish this, we will add 8-10 lbs of lime per cubic yard of soil...
In existing potted plants that need to have pH brought up, you can top dress dolomite. A good rule of thumb is to apply 1 tablespoon of dolomite per gallon of soil i.e. a 3 gallon pot would get a 3 tablespoon application."

They look like brown spots to me. I don't have a link to the leaf deficiency chart but you can google it. Those brown spots look like phosphorous deficiency to me (according to the chart). I am puzzling though this situation myself. I am a light feeder so it may be logical for me. It sounds like you aren't feeding them anything extra so they may be lacking a little P.

Thanks everyone for your help !