Yellow plants

[Benicia Bendele]

I have a system that is only 2 months old. My plants are turning yellow. What nutriance can I add to give the lettuce and basil a boost but not hurt the tilapia?

[RupertofOZ]

Ditto... it's definitely not the iron...

 

But you need to find the cause for your pH... as it will lockout trace element uptake to the plants... and Iron will be the element locked out...

[BenHehle Beamz]

@Nate...Leaf yellowing first appears on the younger upper leaves in interveinal tissues as Iron is immobile in plants.

could you please upload a picture of your plants? it might help. Like Rupert said, Iron would be locked out at high pH, but other elements too.

[RupertofOZ]

Ben, what I meant was that the iron was definitely not responsible for your pH movement....

It could be another deficiency.. especially with your pH... but I'd look to Iron first...

[Benicia Bendele]

I thought about the vile being clean.  My 10 year old helped the day before the 9 reading.  It has maintained 7.5 for 2 weeks now.

Jim S. said:

No, iron is not caustic plus there is only 2% in the Maxicrop.  What are you using for grow media and how many liters or gallons of media are you using?

A PH of 9 doesn't sound right... I would make sure the test vile was clean and retake the test.

What is the source of your water?

[Benicia Bendele]

My plants look great now so that is not my worry.  I think Jim is correct now that I think about it, the vile might have been dirty.  Thanks

BenHehle Beamz said:

@Nate...Leaf yellowing first appears on the younger upper leaves in interveinal tissues as Iron is immobile in plants.

could you please upload a picture of your plants? it might help. Like Rupert said, Iron would be locked out at high pH, but other elements too.

[TCLynx]

If you are seeing sudden jumps in pH.  Take note of the time of day of the different readings as well as algae.  If you are getting low readings near dawn and high readings in the late afternoon, then algae could be causing pH to swing.  I seen algae blooms that will take the pH up to 9.

A large top up or water change can also cause big pH changes.  Take note that you might check the pH of your tap water right out of the faucet and get a low pH reading but that will be a false reading since CO2 trapped in the water in the pipes/underground etc will act as a weak acid and give you a false low reading.  When that CO2 has a chance to escape while flowing around the system the pH will come up to it's actual buffered level.