Newer leaves yellowing, nutrient issues?

[Nico Farmer]

PH up.

 

[coo_kie]

Update: So, I ordered my seeds online and they should've been only two different strains. Now, I don't know If it's just me, but they look like they're 3 different species. Out of 6, one turned out to be autoflowering, two of them are still green with only slight discoloring at the bottom almost unnoticeable and I can tell they're the same. Three remaining: the most yellow one is maybe another type since it's also taller.
Why am I saying this? Because it looks like at least one of them -the most yellow one (first photo on the left) - will finish earlier even though I picked strains that require the same amount of time to flower. This moment of its timeline, besides the high EC probably locking out nutrients, may encourage yellowing. I know they can't be 100% the same, so judge yourself. (Consider that this is only a curiosity)
By the way, I watered them yesterday evening with plain water and PH down. I went by eye 'cause I had some problems with my Apera and got it back today. I had the previous one tough and I did some measurements with that, but I don't even consider the info reliable because since it dropped once in the water it stopped working but when dried it started working again with this strange behavior: in normal measurements it reads slightly lower values than normal, but as soon as I add Ph down it goes crazy and starts showing me PH in the range of 4.0-5.0. Of course, with Apera readings are different showing much closer values if I mach my results with the "acidic power" declared on the label. All this to say: PH values? Next time.
EC readings went fine:
- Input 0.02 (Water collected from the dehumidifier)
- Output (after 25 mins):

1. 3.3 (green one)
2. 5.6 (in the middle)
3. 2.9 (most yellow one)

Hope to see better values next time. And I can see water can be an extremely wide topic.

This are some photos:

-----------------------------------

 

[Cerathule]

By the way, I watered them yesterday evening with plain water and PH down. I went by eye 'cause I had some problems with my Apera and got it back today. I had the previous one tough and I did some measurements with that, but I don't even consider the info reliable because since it dropped once in the water it stopped working but when dried it started working again with this strange behavior: in normal measurements it reads slightly lower values than normal, but as soon as I add Ph down it goes crazy and starts showing me PH in the range of 4.0-5.0. Of course, with Apera readings are different showing much closer values if I mach my results with the "acidic power" declared on the label. All this to say: PH values? Next time.
EC readings went fine:
- Input 0.02 (Water collected from the dehumidifier)

Don't try to pH pure water, this is why your acid caused so heavy a drop measured by your pH pen - there are no alkaline reaction partners within this water. You don't have to pH the water when it is soft like that, around ~0.2mS EC is at least needed for starters

 

[Lumpy-Gravy]

How come yer mucking about with EC and pH in compost? It’s not necessary.

 

[Douglas.Curtis]

I sometimes wonder how many people posting about not being able to test r/o, have ever tested r/o before. Most systems are not at 0ppm and test pH just fine thanks. lolol

I know, 'cause I ran hydro and r/o for almost 20 years and it tests just fine at 3 to 4ppm, right about where most r/o output runs.

It's 7, btw... lol

 

[coo_kie]

I do not consider EC as an absolute value, mostly because as you say, I'm in soil and not in hydroponics. It can be misleading sometimes but in broad terms, "abnormal" values like mine, combined with visual diagnosis, could help identifying the root of the problem.
The electrical conductivity of BioBizz Light Mix is 1.2, so even if I didn't want to take too seriously all the runoff readings, they still show that something is not working properly and the soil may be too rich of minerals.
So far the problem here is: nutrient deficiency (we made it clear that they need some micro and macro nutrients such as Ca, Mg, Fe, N, some P and K).
The root of this problem: the hard water --> salt buildup. And, of course, also because of me not giving them nutes.
(Correct me if I'm wrong).

Next time I'll go with nutrients to those that are yellow, but I think it will be the penultimate time or so (at least for the one that seems closer to harvest).
I'm open to suggestions for the next waterings.

Don't try to pH pure water, this is why your acid caused so heavy a drop measured by your pH pen - there are no alkaline reaction partners within this water. You don't have to pH the water when it is soft like that, around ~0.2mS EC is at least needed for starters

New thing learned. Thank you. So, do I have to lower it in other ways or it's just fine and it will lower by itself when added to soil? @Three Berries pointed out that whenever soil dries, acids in the nutes get more concentrated and make PH drop. How about R/O and rainwater or water without nutes?

I know we're going much into details, but I hope this will be useful to other people as well.
Of course, if you have some articles that may be worth reading, tell me.

 

[Lumpy-Gravy]

I think water that hard is possibly nigh on useless. 4.5 from the tap?! Does it come out as limestone lol If you are using reverse osmosis water just use that and calmag your RO water. Dump that rock water.
The other thing is 23 degrees is far to low. You’ll get lockout with cold roots.when I saw the pics without reading the first thing I thought was too cold.
It’s all well and good messing with nutes, EC, ph etc etc if the environment isn’t right.

 

[Cerathule]

I do not consider EC as an absolute value, mostly because as you say, I'm in soil and not in hydroponics. It can be misleading sometimes but in broad terms, "abnormal" values like mine, combined with visual diagnosis, could help identifying the root of the problem.
The electrical conductivity of BioBizz Light Mix is 1.2, so even if I didn't want to take too seriously all the runoff readings, they still show that something is not working properly and the soil may be too rich of minerals.
So far the problem here is: nutrient deficiency (we made it clear that they need some micro and macro nutrients such as Ca, Mg, Fe, N, some P and K).
The root of this problem: the hard water --> salt buildup. And, of course, also because of me not giving them nutes.
(Correct me if I'm wrong).

Next time I'll go with nutrients to those that are yellow, but I think it will be the penultimate time or so (at least for the one that seems closer to harvest).
I'm open to suggestions for the next waterings.


New thing learned. Thank you. So, do I have to lower it in other ways or it's just fine and it will lower by itself when added to soil? @Three Berries pointed out that whenever soil dries, acids in the nutes get more concentrated and make PH drop. How about R/O and rainwater or water without nutes?

I know we're going much into details, but I hope this will be useful to other people as well.
Of course, if you have some articles that may be worth reading, tell me.

When you water with rain/RO the water will just be there to dilute the soil solution so there will be no crude changes in its properties.
But then the soil must hold all essentials latently and gradually release those into solution.
Otherwise you gotta feed, and depending on your fertilizer you may have to adjust or not.

 

[Cerathule]

I sometimes wonder how many people posting about not being able to test r/o, have ever tested r/o before. Most systems are not at 0ppm and test pH just fine thanks. lolol

I know, 'cause I ran hydro and r/o for almost 20 years and it tests just fine at 3 to 4ppm, right about where most r/o output runs.

It's 7, btw... lol

You shouldn't even consider to stick a pH pen in such a low-EC water because it can damage the probe. It's also pointless to try to figure out its "potential of hydrogen" when said fluid just underwent a clearing process that removed almost all ions.

 

[Three Berries]

My well water is 500 ppm this time of year with our drought. I cut it in half with rain water to use in the soil mixes. Straight though in the Ocean Forest and auto this time.

 

[coo_kie]

I think water that hard is possibly nigh on useless. 4.5 from the tap?! Does it come out as limestone lol If you are using reverse osmosis water just use that and calmag your RO water. Dump that rock water.
The other thing is 23 degrees is far to low. You’ll get lockout with cold roots.when I saw the pics without reading the first thing I thought was too cold.
It’s all well and good messing with nutes, EC, ph etc etc if the environment isn’t right.

I'm not going to use that water any further.
Speaking of temperature, I mean 23°C (73° F), maybe you assumed that was fahrenheit?

When you water with rain/RO the water will just be there to dilute the soil solution so there will be no crude changes in its properties.
But then the soil must hold all essentials latently and gradually release those into solution.
Otherwise you gotta feed, and depending on your fertilizer you may have to adjust or not.

So you're saying that rain/RO water should maintain its PH which should be balanced by (good) soil, unless mixed with hard water/nutes?

 

[Lumpy-Gravy]

Your root zone wants to be 22ish. Get a heat mat. The air temp wants to be at least 27 under LED. I try n keep leaf surface temp at 26/27 if I can. It’s worse that your lights off is 18. Your root zone will be at least a couple of degrees lower. You can throw all the feed n that at it but if it’s too cold it’ll not do owt n things will get worse. Bang the heating on

 

[Cerathule]

So you're saying that rain/RO water should maintain its PH which should be balanced by (good) soil, unless mixed with hard water/nutes?

It's rather that RO is a good approximation of pure water that is neutral in its behaviour and doesn't add any basicity or alkalinity to the substrate. The RO is actually slighly acidic due to the presence of atmospheric CO2 in solution. But it is so little that it won't bring any shift in the H+ balance of the substrate and its solution.

 

[aliceklar]

Keeping things simple, I would just try using rainwater and see what difference that makes. I had some awful troubles in my last grow with hard tapwater - I was using initially citric acid as pH down and although it worked temporarily, after about 12 hours the pH had bounced back up again. I ended up treating the tapwater with nitric acid as pH down, then diluting it with rainwater. That did the trick.

 

[Three Berries]

The carbonates in hard water act as buffers, or slow acting pH adjustments so they will climb after sitting a while usually. And you should leave the mixed and pHed nute solution open so the CO2 that is generated dissipates for a few hours to get a truer reading.

My latest rainwater has a pH of 7.2, rather high. PPM is 25.

 

[OZZ_]

On your next grow, Just use RO water with cal mag as your base water source and all these issues will go away. It’s your ridiculously hard water messing everything up, as others have said.

As a side note I watered some outdoor chili plants with biobizz the other day, just trying to use up some old nutes…. it took 36 ml of the stuff in one gallon of water to get to a 1.7 EC reading. PHd to 6.5

Adding 1 ml here or there isn’t going to do anything the stuff is horribly weak.

Try Cannas bio Vega and bio Flores. Great stuff works fantastic in soil.

But first you need decent water to start with

 

[coo_kie]

Update: sorry if I didn't reply for a while, things are still pretty much the same: they've lost I think 25-35% of their foliage but I also noticed they were almost all ready. By this time I harvested two of them and I'm gonna use just plain water for the other three.
They developed many brown spots on new leaves as the deficiency progressed, but I also moved the light slightly further from the plants just to be sure they aren't stressed by too much light.
I'll start over with the water I'm currently using. I feel a bit bad because they started really great and they did good overall, but I could have treated them better.
Hope the next time I won't be writing about nutrient issues again
Thank you all for your time and effort covering this problem

 

[Creeperpark]

I sometimes wonder how many people posting about not being able to test r/o, have ever tested r/o before. Most systems are not at 0ppm and test pH just fine thanks. lolol

I know, 'cause I ran hydro and r/o for almost 20 years and it tests just fine at 3 to 4ppm, right about where most r/o output runs.

It's 7, btw... lol

RO water once had a pH and thats why you can get a reading. However distilled and rain will give false readings using a pocket pH pen.

 

[Cerathule]

It's just impurities enable the measurement. Ideal RO has no pH as it's just neutral H2O but a bit of atmospheric gases in equillibrium in it in various dissociation phases. But it could be kept hermetically locked to stay pure H2O.

 

[Cerathule]

As a side note I watered some outdoor chili plants with biobizz the other day, just trying to use up some old nutes…. it took 36 ml of the stuff in one gallon of water to get to a 1.7 EC reading. PHd to 6.5

Biobizz is organic - you cannot fully measure its EC. Not even close - about only 30% of it is prefermented.
You just fed about EC +5 in latent nutes.