Looks like Cal and Mn something, HYDRO

[scegy]

Hello everyone!

i could have let this by, but i'd really like to have good healthy plants all the way, so i'm adressing all that had simmilar looking problems, to share their story

now my title says that i have an idea what's going on, but as u know, I am not always right hehe
saying that because i've noticed that "same old Cal problem" when necrosis is present in circle patches with a yellowish background

but besides that there are also some other necrotic patches that are different from Cal problems. I've been running on 6.1-6.2 pH regime for the past 2 weeks, and since high pH(around 6.5) was supposed to lead to Mn problems i've started feeding with a pH 5.5 solution today to lower the system's pH under 6.1

i've also added a little cal yesterday and a day before (0.5 ml/L of the feed reservoir(20L) ) since i noticed these signs

also been adding Mg at 0.5 ml/L of the additional res

so to give u a wider perspective....

HYDROPONICS:

What STRAIN are you growing? Mango and Blue Moon Rocks, both indica phenos
What was the establishing technique? (Were the seed or clone?)
clones from a mother
What is the age of your plants?
11 weeks old, 6 weeks on 12/12
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in?
flowering
What Technique are you using?
recirculative DWC("biobucket")
What substrate/medium are you using?(Hydroton, RockWool etc.)
mediumless, plastic foam
What is the Nutrient temperature?
22-23°C
What Nutrient's are you using?
Canna Aqua flower
What is the TDS/EC/PPM you are using?
EC 1.62
What is the pH of the "Tank"?
pH 6.22
Are you sure your calibration is correct on your equiptment?
calibrated it 1,5 month ago, so +- 0.1 to be sure
When was your last watering?
float valve supplys fresh water and nutrients if needed 24/7

When was your last feeding change? (ie. grow-bloom-micro-additional)
1 week after switching to 12/12 i switched grow to bloom
What size bulb are you using?
400W
What is the distance to the canopy?
15-20 cm, using a heat spreder
What is your RH Factor?
50-60%
What is the canopy temperature?
22-25°C
What is the Day/Night Temp? (Include flucutaion range)
in the grow room it's 22-25 day/night
What is the current Air Flow? (cfm etc.)
~250 m3/h
Is the fan blowing directly at plants?
yes
Is your water HARD or SOFT?
soft, RO water, tap water in veg
Has plant been recently pruned, cloned off of or pinched
not in a big way, just a few pinches now and then
Have any pest chemicals been used? If so, What and When?
was sprayed with spinosad in the early veg state to eliminate thrips buildup in flower
Are plant's infected with pest's
no

here's a link to my thread, maybe u'll see something that i've overlooked
http://www.icmag.com/ic/showthread.php?t=40143&highlight=scegy


so here are the pics
it's on the both strains so that's not an issue, must be something chemically
it has progressed in the past week so my next guess would be to feed only water for a few days, what do you think?

also the leaf tips are slightly burned, which could, again, indicate that there are excessive ions in my system

p.s. i've looked over my notes and i've been adding Mg constantly for the past 3 weeks before this showed up, so it might be Mg related problem, pushing out Cal def.

let's hear you out ppl, thank you in advance!

 

[MynameStitch]

There is only a few things I see wrong, 3rd picture from left to right..... I see light bleaching.... check the bottom right corner of the picture you will see some bleaching....


15-20 cm is pretty close even for a 400 watt hps.
I would have moved the light up a bit. I noticed that the most of the issues are on the upper part of the plant?

Calcium mostly starts on the leaves edges then works it's way inwards on the leaves.... but that does not mean this is not.
I would make sure your ph stays below 6.1....... I think canna aquas has calcium not 100% sure will have to double check. I would make sure your ph stays stable then add a bit of calcium if needed.... calcium is best absorbed in ph the 5.3-5.8 range... you may have been causing a slight lockout... if not then your light is causing some radiant heat issues. That amount of magnesium will not cause an imbalance of calcium.
SO I would move the light up a bit, balance ph checking regularly. I would also re- calibrate your meter... mine would come out of balance about every 2 weeks.. I would check it 2 times a month rather than every month 1/2.

Is this problem on the top area of the plant only or anywhere else?

 

[scegy]

hey stitch
you'r right about the light, there was some bleaching but i raised it few days ago, so that's solved

yes canna has cal, it's just that i feed them with a lot of RO water which doesn't have Mg or Cal, so i replace that with adding mg or cal sometimes( i do that in veg, with diff. brand nutes, go hand in hand with tap water)

after i posted my problems i went and calibrated my ph, and it was off for 0.15 point, so that's been solved too

and yes plants are affected in the upper part, below is just a minor lack of N which is normal for this stage(yellowing leaves and dying)

i'm glad u'r pretty much with me on this one
i'm gonna feed them just ph-ed water for the next few days and i'll see what happens

thanks dudette!

 

[MynameStitch]

If they get any worse they need calcium. I just do not want to say go add calcium when your ph was a little off.

So if it progresses get some calcium added to it

Lighting can leave the patches it has left on your plant now; I have seen light issues get confused with calcium issues.... calcium is usually not on the top part of the plant but the middle. But now that you have moved the light up your problem should have gone away. As long as you keep track of your growth of your plants to the closeness of the light


Good luck with everything

 

[scegy]

so that's it, that simple? hehe, buds look a little bit better today i think, we'll know more i n time, thank you stitch!

 

[MynameStitch]

Anytime, let us know how things go

 

[scegy]

hey there stitch!
i finally figured it out what's the matter, as i was adding my MgSO4 + Cal to my RO(supposed to be Mg/Cal-less) i didn't realize that my RO unit gives me out 0,6 EC aka ****ed, stuffed with minerals, that's because i've tried to use my ro unit without wasting water, so the filter got full off ions that are passed on not flushed out like they usually are

so i was thinking on installing a charcoil filter on the RO's waste line and using that water in my dwc as i don't need sterile water, just no ions

so this was a typicall case of Mg-Cal overdose and nothing more, still i'm gonna have pretty nice buds in a week so i'm down girl!

thanks for ur interest!

 

[MynameStitch]

You are supossed to change our your RO filter ever so often, when was the last time you changed it?

How much were you adding to your water anyways?

 

[scegy]

i monitored the outcome water with EC meter, and i haven't done that since i modified my filter..

hehe the last time i changed it...never after 3-4...5? years it still gave me a 0.1 EC outcome, good enough, but as said i'm not using RO anymore, it's unnecessary, just carbon water softener

i was adding about 0,25 ml /L every time i refilled the outside water reservoir for the past ~3 weeks, not knowing that i'm actually adding full tap water that already has a lot of mg+cal, anddd, you must consider the mg+cal that is in the nutes, sum those three up and u get what i got

we'll c next time if i'm right, but i'm pretty sure that this is what happened

 

[MynameStitch]

Cause it's extremley rare to get magnesium and calcium toxcity which was why I was asking......
I have seen peeps use 250 and a little more ppms of hard water and the plants did not show symptoms like your plants did..... so Idunno, it's very rare and I have never seen cal and mag tox before.......

What ppms were you getting with just the tap water and the mag and calicum you were adding? Nothing else no nutrients just the water and cal mag