Anyone think this yellowing is from over watering

[Shayne010944]

 

[Shayne010944]

was running 0.4 ec for first week and slowing have gone up to 0.8ec as i thought they looked hungry .

they seem a little yellow in this system.

watering was 30 seconds every 2hrs ( lights on ) - but i have just changed this to 30seconds every 5 hrs lights on now - no watering lights off

also using GH trio - micro grow bloom. PH at 6.0

Spider farmer 4000 at %50 intensity now and about 32inch high from plants.

this run seems harder for some reason.

seedlings were started in small rockwool cubes and placed into the hydroton

temps around 22-25 degrees celcuis - its been cold here . RH %47-%55 i been trying to get it up more by using a timer on my exhaust to only come on 15min every 1 hr now.

@Moe.Red @Aqua Man

 

[Aqua Man]

Less light higher ppm is where i would start

 

[Aqua Man]

How big of RW cubes?

 

[growsince79]

was running 0.4 ec for first week and slowing have gone up to 0.8ec as i thought they looked hungry .

they seem a little yellow in this system.

watering was 30 seconds every 2hrs ( lights on ) - but i have just changed this to 30seconds every 5 hrs lights on now - no watering lights off

also using GH trio - micro grow bloom. PH at 6.0

Spider farmer 4000 at %50 intensity now and about 32inch high from plants.

this run seems harder for some reason.

seedlings were started in small rockwool cubes and placed into the hydroton

temps around 22-25 degrees celcuis - its been cold here . RH %47-%55 i been trying to get it up more by using a timer on my exhaust to only come on 15min every 1 hr now.

@Moe.Red @Aqua Man

it should be almost impossible to overwater that. Agree with Aqua, increase nutes raise light for now.

 

[Shayne010944]

How big of RW cubes?

they are only 1 or 2 inch square blocks they very small

 

[Aqua Man]

they are only 1 or 2 inch square blocks they very small

Yeah id up the ppm to about 1-1.2 EC . If the roots are out of the cubes as I suspect you will need to water much more frequently… like @growsince79 said it would be extremely hard to overwater them

 

[Shayne010944]

Yeah id up the ppm to about 1-1.2 EC . If the roots are out of the cubes as I suspect you will need to water much more frequently… like @growsince79 said it would be extremely hard to overwater them

Yeah thank you. Just upped it to 1.0 ec and raised the light . See how it takes in next couple of days

 

[Shayne010944]

Raised the light up

Ec at 1.0 now . 11 days in the Wilma system

I think new growth starting to green up ? Or am I just thinking that

 

[Shayne010944]

any ideas @Moe.Red

 

[Aqua Man]

Looking better to me

 

[Shayne010944]

Looking better to me

thanks aqua - it seems very light amount of nutes as opposed to having 60 Litres of water in this tank . i reckon ive only got 20ml micro - 20ml grow and probably 10ml bloom in the whole tank.

i am also using great white powder - not sure if i need to add anything else.

when i dump the rez in a few days ill be using the schedule which calls for 1/2 teaspoon per gal of each

so 2.49ml per gallon - tank is 15.8 gal - ill be adding 38.8ml micro / 38.8 grow and 38.8 bloom - using the GH trio

 

[Moe.Red]

any ideas @Moe.Red

Sure, lemme look up the Wilma system, never heard of it. Are you 100% hydroton? Pumping 100% of the time?

 

[Moe.Red]

Is that the

WILMA XL 4 COMPLETE 25L​

Wilma systems - Atami

Complete growing systems for every type of grower! Available in various sizes Lightweight system which makes them easy to transport Stable design, allowing easy placement Automatic watering, which allows a perfect water/nutrition ratio Manual watering is no longer needed FOR PERFECT...

atami.com

So basically it is just a res with pots on top and you water thru the 1/4 tubing and it drains to the res, correct?

 

[Moe.Red]

This is where you want to be environmentally at this stage:

Although this assumes 1*C difference between ambient (which I assume is the measurement you gave) and leaf temp. That's probably pretty close with your light turned down and so far away, but as you get on track and start to pour on PPFD this chart will change for you.


You want to be about 1 kPa right now.

The reason I bring up VPD is that your leaves are curling. Can I get a current measurement of temp and RH, how long the lights have been on, and even better if you have an iR temp gun in your toolbox, shoot the leaf and give me that temp.

VPD sets respiration of the plant. What I suspect is that you are too cold and too low RH at this point. I suspect your VPD is high:

When VPD is too high, you essentially starve the plant even when they are bathed in nutrients. No respiration, no nutes up the stalk.

Obviously there are degrees to this, you are not killing the plant, some respiration is happening. Photosynthesis is occurring. Just not enough.

I'll comment on the nutes after I hear more on the questions above.

 

[Aqua Man]

This is where you want to be environmentally at this stage:

View attachment 1281888

Although this assumes 1*C difference between ambient (which I assume is the measurement you gave) and leaf temp. That's probably pretty close with your light turned down and so far away, but as you get on track and start to pour on PPFD this chart will change for you.


You want to be about 1 kPa right now.

The reason I bring up VPD is that your leaves are curling. Can I get a current measurement of temp and RH, how long the lights have been on, and even better if you have an iR temp gun in your toolbox, shoot the leaf and give me that temp.

VPD sets respiration of the plant. What I suspect is that you are too cold and too low RH at this point. I suspect your VPD is high:

View attachment 1281889

When VPD is too high, you essentially starve the plant even when they are bathed in nutrients. No respiration, no nutes up the stalk.

Obviously there are degrees to this, you are not killing the plant, some respiration is happening. Photosynthesis is occurring. Just not enough.

I'll comment on the nutes after I hear more on the questions above.

Yeah he is definitely on the edge of cold but under his lights i cant see it being 1f different… if i were to bet id say around 3-5f difference.

since he doesn’t really have a way to get these inline right now by the sounds of things by reducing light he reduces the transpiration stress and nutrient demand.

but compare the first set of pics and the second… id be curious to see his ppfd readings

 

[Shayne010944]

Is that the

WILMA XL 4 COMPLETE 25L​

Wilma systems - Atami

Complete growing systems for every type of grower! Available in various sizes Lightweight system which makes them easy to transport Stable design, allowing easy placement Automatic watering, which allows a perfect water/nutrition ratio Manual watering is no longer needed FOR PERFECT...

atami.com

So basically it is just a res with pots on top and you water thru the 1/4 tubing and it drains to the res, correct?

yep thats it but i have a 60L tank - 18L pots.

started these in rockwool cubes they are 1-2inch sqare only small. and into hydroton

 

[Shayne010944]

my temps are around the 23degres and up to 25degrees - i was having low %RH so i turned the exhaust on a timer to come on 15min every hour

%RH has gone up to %65

i dont have a IR gun

lights on 18 and off 6 at %40-%50 intensity

watering 30seconds every 2hrs on timer

 

[Moe.Red]

Have you used this system successfully before?

 

[Moe.Red]

So your VPD now is better. I like the higher RH at this stage.

30 seconds seems too short and 2 hours too long to me. Seems like with nothing but hydroton there is no way to get them wet enough and keep them wet. I'd worry about my roots drying out. I don't think you can overwater at this point, but you could underwater.

The only drawback I see to running the pump more is possibly heating the water too much. What are the black hoses going out of picture? Is that a chiller or filter or something?