chlorotic ringspot?

[MDpulp]

Hi everyone

long time reader 1st time poster... and I ll take this occasion to thank all the contributors, I have learnt so much and still am!

on to my issue

I can t figure out what s causing those spots

apparently i can t post links to my picture gallery (yet?), so please look it up ><

/gallery/data/500/32659ringspot_top.JPG
/gallery/data/500/32659ringspot_bottom-thumb.JPG

it s happening on 4 different strains vegging together
It s obviously still early but spreading nonetheless

those spots under the leaves have a silverish look that doesn t come out well on pictures. it can t be washed, rubbed or scratched off

3 weeks old plants (from seeds) vegging under t5s 18/6 (on their 5th node)
recirculating top drip on rockwool cube / hydroton

nutrients: canna aqua vega, cannazyme, rhyzotonic (following canna schedule) + some h2o2 (@35% 0.5 to 1ml /l every other day)
EC @ 1.4 (total) (mixed tap water/ RO 50/50 for a base EC of 0.25)
pH 5.7-6.1
Temp 68-80
RH 60-80

no pest visible (checked with a magnifier)

Does anybody have a clue as to what s causing this and how to fix it?

 

[Skipload]

How is the air circulation and humitity. Have you considered molds and chemicals splashing on the leaves, even from lets say the drippers splashing on the pebbles.

 

[MDpulp]

Hi Skipload, thanks for your input.

Humidity hovers between 60 and 80%

Air circulation is plenty, plants are in a 1m² homebox with two circulating fans and extraction is a 300 cubic meter per hour rvk, passive intake.

drippers arent splashing

it could be mold, but hydrogen peroxide doesn t seem to remove it and it doesn t rub off?

 

[Skipload]

Can u provide a pick of the entire plant? The only other info I have, from the info you gave me, is P def. During veg P def looks like mold, there should also be brittle tips showing or starting to show though.

 

[Koskesh]

3 week old plants eh? how long you been givin them 1.4 ec? at what conversion? imho mfg feed schedules are always too strong. check your runoff lately? 80% hum sounds a bit high. which leaves are most affected (top, middle, bottom, older, newer)? and yea like skip said a full plant shot would help a lot, including the medium and roots if poss.

 

[MDpulp]

Hi Skip,

It doesn t look like any P deficiency pic i have seen and no brittle tips so far.

Unfortunately I don t have a camera to post full plants pic atm.

Hi Koskesh,

The drip is constantly on, so runoff isn t relevant, the system is kinda like a homemade waterfarm. Roots coming out of pots are bright white and look healthy, rockwool cubes have some algae on top, which in my experience usually goes away when light stop reaching the cubes.

Conversion is at 0.5 i believe for 700ppm, feed was increased last week, i guess i will dilute it some just in case.

I gave them some high pH foiliar with neem oil and h2o2 last night (slightly burnt some foilage... ) hopefully killed whatever it was the process...

I guess i m going to wait a couple days and see how things evolve before i do anything else.

I will try to get a hold of a camera for some pics

for now i can link my original leaves scan (yay!)

 

[MynameStitch]

You know what, I would be very careful using that rhizotonic, I don't care what canna says.... I have seen so many plants not like constant feedings of it... I would back off on it a bit; but I highly doubt that is what causing this... if I were you, I would ignore it for now cause as long as it's not spreading to other leaves it won't be a problem.... a lot of times strains will show genetic flaws where certain areas will not have chlorophyll and have mutations.... so please do not do anything and just wait and see what happens...... giving too much love for something small will end up with a worse problem ....... give it time first.... trust me i know how you are feeling, you want the best for them.... sometimes too much love carries problems so just wait a bit ok

as for the rhizotonic I would be using it only once every week and 1/2

ALso when leaves tend to look like the way they do in your pictures, it always ends up being something was dripped on the leaves like nute mix or something else... or it ended up being a mutation in the plants dna code... so ya the best thing to do is wait a bit

depending on how big the plants are I would watch the PPM... you go by plant size but since your using canna, I would not really worry about it since there feeding regimen is normally right on the money... but if you were using some other nutrients not cannabis specific I am sure you may have a burn by now..... and smaller plants!

 

[MDpulp]

Hi Mynamestitch

I ll take your advice and lay off the rhyzo after the first couple weeks from now on.

I was concerned because those spots were on more than a few leaves, on different plants from different strains, and it wasn t due to splashing.

Started with tiny white spots under the leaves, really weird stuff

After the foliar treatment (too heavy on peroxide which caused some minor burns) it has stopped spreading and hopefully won t be back.

Much love for all the help you are giving in these forums.

 

[MynameStitch]

Your rh was 60-80%?

That is way too high, why is it going up and down like this?
You keep it that range you will be sure to have other issues.......

 

[MDpulp]

Isn t 60% RH a good target for a veg chamber?

It s been raining past few days, i guess that s what spiked it. I ll keep an eye on it, what range would you recommend ?

 

[Koskesh]

i don't like to ever go below 40 or above 60 rh.

 

[MynameStitch]

Like koskesh said, but to be on the safe side I always say not to go over 55% some strains are more resistant to molds and fungus, and some other strains can get mold mildew past 60% rh.... so no lower than 40 and no higher than 55% to be on the safe side for flowering.... if you know the strain is strong against molds and fungus then 60%RH will be fine.