Calcium lockout? *Hydro grow, DWC*

mixchemical

mixchemical

Active Member
Hey all!

I've just recently (about 2.5 weeks ago) started up my first DWC grow and 2 of the plants are doing great but one of them is showing signs of Ca deficiency. See pictures.

Im running tapwater with GH trio (micro, gro and bloom) and pH'ed down to 5.8 (I add micro first, stir and then the rest).

The ppm is currently at 450ppm (15L of water) and the pH is at 5.81 and it's been at that pH since day one in the bucket.

Some charts show that calcium is absorbed from 5.0 to 5.8 and some show from 6.0 and above. What's correct? Since the other plants are doing just fine with the same pH, same ppm and same water. I'm just not getting it.


 
bobtokes

bobtokes

Well-Known Member
i would let the ph drift up to 6.2 a couple of times a week, you may have different pheno types, thats why the others are ok
 
OldMedUser

OldMedUser

Well-Known Member
How many leaves is that happening to?

If it's only a couple don't worry about it unless it spreads to the rest of the plant. That could be from being close to the bottom where it's moister and it's picked up a little fungus.

Lots of things can cause a few spots on some leaves but everyone blames Ca right off the bat and it's not as common a problem as it's made out to be. It gets to be more of a problem when people listen to the well-meaning but misinformed helpers in here and toss lots of extra CalMag at it.

pH it down a bit if it likes to rise and let it come back up. Adding too much pH up or down trying to hit a specific target is the cause of many problems.

Nice little nute problem chart by Jorge Cervantes here and it shows that a lot of deficiencies or excesses cause spots as a symptom. If you have one of his grow bibles there is much more detail about which does what that can help the investigator narrow down the problem and come to a more exact diagnoses.

Maybe it's just because you use nutes made by Scotts Miracle-Gro/Monsanto soon to be Bayer that is the real cause of any issues. I use AN's pH Perfect nutes and never see stuff like that in DWC or soil grown plants.

What's the ppm of your tap water? Don't forget to subtract that ppm from the total to know how much of it is actually nutes. Most tap water has more than enough Ca and Mg in it for the plants and adding more blocks many micro-nutrients that can also cause spots tho mostly in younger leaves. Lots more stuff like high sodium, iron and manganese can also block other nutrients and cause all sorts of problems. Contact your water provider for a free copy of their water analysis reports that can change according to the season. I use RO water only and eliminate almost all causes of grief.

Good luck and good growing!

:peace:
 
Last edited:
mixchemical

mixchemical

Active Member
OldMedUser said:
How many leaves is that happening to?

If it's only a couple don't worry about it unless it spreads to the rest of the plant. That could be from being close to the bottom where it's moister and it's picked up a little fungus.

Lots of things can cause a few spots on some leaves but everyone blames Ca right off the bat and it's not as common a problem as it's made out to be. It gets to be more of a problem when people listen to the well-meaning but misinformed helpers in here and toss lots of extra CalMag at it.

pH it down a bit if it likes to rise and let it come back up. Adding too much pH up or down trying to hit a specific target is the cause of many problems.

Nice little nute problem chart by Jorge Cervantes here and it shows that a lot of deficiencies or excesses cause spots as a symptom. If you have one of his grow bibles there is much more detail about which does what that can help the investigator narrow down the problem and come to a more exact diagnoses.

Maybe it's just because you use nutes made by Scotts Miracle-Gro/Monsanto soon to be Bayer that is the real cause of any issues. I use AN's pH Perfect nutes and never see stuff like that in DWC or soil grown plants.

What's the ppm of your tap water? Don't forget to subtract that ppm from the total to know how much of it is actually nutes. Most tap water has more than enough Ca and Mg in it for the plants and adding more blocks many micro-nutrients that can also cause spots tho mostly in younger leaves. Lots more stuff like high sodium, iron and manganese can also block other nutrients and cause all sorts of problems. Contact your water provider for a free copy of their water analysis reports that can change according to the season. I use RO water only and eliminate almost all causes of grief.

Good luck and good growing!

:peace:
Click to expand...
Thanks for the thorough reply!

It started at the first set of true leaves but now it has spread to the next set of fan leaves that are the biggest (i.e the second set of true leaves that has formed).

Well since the amount of water (15L in this case) needs quite a bit of pH down to get it below, since my tapwater has a pH of about 7.5 and the nutes only bring that down to about 6.8 or thereabouts.

The roots however look fine, but if im judging from just comparing this plant to the other 2, seems like growth isn't happening as fast as the others.

The ppm of my tapwater is 65ppm and also, the pH has risen from about 5.81 to 5.9 over night, i'm gonna let it travel for the rest of the day and see when I get back from work.
 
mixchemical

mixchemical

Active Member
Alright, the pH is climbing slowly, now sitting at 5.97 yet the problems continue and seem to get worse (see pics). Is this really only a Ca deficiency or something else? I'm also seeing stunted growth compared to the other 2 plants, this one hasn't seen much grown in 1-2 days where as the other two are noticably bigger.

Roots are white and no slime etc. The res is changed ever 7 days.
 

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mixchemical

mixchemical

Active Member
Yesterday I changed out the whole res. with new water and nutes, pH'ed it down to 6.0 but still the problem persists. Shall I just go ahead and change the res. with just water and no nutes? I really don't get what's going on with the plant :/
 
OldMedUser

OldMedUser

Well-Known Member
Don't use just water. That can cause the plant to reverse the flow of ions and it will basically dry out and die.

I'd just give it some time. Could be it's got some genetic problem and just won't recover. I'd had a few like that over the years and there isn't much else to do if that's the issue.

The newer growth looks decent so it may pick up and get going if it's not killed with too much TLC. If it's got a decent level of balanced nutes it should come back. Takes more than a day for changes to become obvious.

:peace:
 
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