Drip irrigation and auto injector question

[renegade66]

I have 3 plants this year setup in side a basic greenhouse constructed off the side of my garage.

The strains are Afghan Kush, Northern Lights and Runtz OG from left to right in picture.

I have a exflow 2.5 gal auto injector set on slow which is micro dosing them approx a teaspoon of miracle grow at each watering.

Each plant has four micro drip heads in a square pattern equally spaced around the main stalk that have a 0.9gph rate.

My growing medium is about 6 inches of "garden mix soil" sitting on top of a clay bottom with landscape fabric then mulch on top.

Total flow rate to all heads is 0.9 x 12 = 10.8 gallons per hour
Flow rate to each plant would be 3.6 gallons per hour
This works out to be 0.06 gallons per plant per minute of run time

I have been giving them 40 minutes per day of run time or 2.5 gallons per day divided in equal doses every 4 hours leaving the injector
on slow setting.

All the plants started flowering last week.

I am noticing the Afghan plant has the very tip of the fan leaves yellow and the northern lights is turning leaves upside down or sideways.

My first question would be I am i giving them too much water too often, should i go to a 12 hour twice a day schedule at a lower amount?
My second question is it possible i have nutes built up in the soil?
If it is nutes built up should i turn off the injector and continue the same schedule with just water or should i do a long flush with water and stop watering for a day?

The injector is charged with 1 bag of 24-8-16 and one bag of 15-30-15 and it outputs at a rate of about 1 teaspoon per gallon of water flow.

There are 4 fans maintaining airflow in the space, 2 moving air inside and 2 moving outside air in.

Here are the pics of the grow space and the buds forming, the northern lights does seem to be ahead of the Afghan Kush and the Runtz but they are all flowering some closeup pics of the buds may look more yellow or lime green than they are due the flash on my camera.

This is my fourth grow in this space I normally have 4 plants but lost one this year due to a bad clone, my crop has been pretty well steady every year at 1 lb per plant or 4 lb total.

 

[Buzzzz]

Hard to tell by the pics they don't look that bad but it does look kinda cramped for airflow and competition. Maybe buy a moisture meter to establish a baseline to time watering cycles,you may very well have salt buildup feeding them every watering and your PH may not stay stable and can cause leaves to turn upside down as can harsh feeding and humidity,underfeed them and work up,defoliate when they come around at the bottom. Let the medium dry and flush them with PH adjusted water. Just my 1/2 cent. Maybe someone else will have a better suggestion.

 

[renegade66]

Hard to tell by the pics they don't look that bad but it does look kinda cramped for airflow and competition. Maybe buy a moisture meter to establish a baseline to time watering cycles,you may very well have salt buildup feeding them every watering and your PH may not stay stable and can cause leaves to turn upside down as can harsh feeding and humidity,underfeed them and work up,defoliate when they come around at the bottom. Let the medium dry and flush them with PH adjusted water. Just my 1/2 cent. Maybe someone else will have a better suggestion.

Yes they are monsters this year but there is plenty of airflow in the greenhouse.

I turned off the auto feeder, they will get 10 mins of fresh water in an hour then I am going to stop watering until the bed dries out and see how they respond then I am thinking of going to an every 12 hour watering schedule to let it dry out more between cycles.