MegaCrop +CoCo Early flower problems

[MesaBoogie]

Hi, I've been having some issues with Mega crop 2.0 and my 60/40 Coco/perlite mix. As soon as my plants start to flower I'm plagued with rust spots. They come on really fast starting towards the upper part of the plant. I've ran a few different cycles with varying genetics of auto flowers and tried different methods to combat this to no avail. I should also mention around the 3rd week of flower I add half a tsp of AN's Big bud.. Seems to make no difference to the progression of the spots.

Things I've tried on different plants:

-Lets start with PH. I initially started going with 5.8 to 6.2. I've since changed it up to running 5.7 to 5.9 on all my plants.
-Cal/mag: I've tried going from 1tsp per gal to 1/2 to 1/4 to no extra cal/mag. Hard to tell but it seems like no extra cal mag is slightly better.
-Epsom salts: On my most recent plant I tried 1/4 tsp/gal and up to 1/2 tsp gal with no cal/mag added when Epsom salts used.
-MegaCrop: I keep to under 4g/gal.. Lately I've cut back to around 3.2 to 3.5grams per gallon. Run off is always around 800 ppm. Water ppm comes out of the tap around 300ppm and 7.5ph.

here is a link to whats in my water:

Water Quality Characteristics | Saskatoon.ca

Water Quality Characteristics

www.saskatoon.ca

My most recent plant starting to flower (Fastbuds: zkittlez auto)
My last feed was 3.3 g/gal MC, 1/4 tsp Epsom salts, 1/4 tsp Big bud. Was about 800ppm total including 300ppm of tap water. Just before flower this girl looked nice and green.

Here she is 1 week earlier Feeding 3.2g MC only @5.8 PH 2 days later the rust started to show. Next water added 1/4 tsp Epsom and rust progressed.

it will progress to look something like this

Thanks for any help/feedback ! I've only done a few cycles of both coco and mega crop, if I can sort this issue out it would be great !

 

[karlkutta]

I'm interested to hear about this. I started using MG in soil and going to try coco now. My first seedling never took though. Are you adding calmag in veg? I am doing 5ml in my soil grows, the plants seemed to like it.

I'm interested to hear what others experienced. It's a downer when these plants show these sings.

 

[Waira]

MB mate, I'm not so sure this is Ca defc.,... a known problem with MC, it's micronute weak (it seems judging by the number of cases I see in here), K heavy which fucks with cation/micronute uptake... Too much Ca-Mg does the same thing, Ca blocks Mg, visa-versa, and others (look at page 2 in the Defc. Pic Depot at the nute excess charts, Mulders Wheel of Confusion too) ... You'll see what I mean!
MC has plenty of Ca-Mg in it alone, more is making matters worse,... epsoms an overkill! ....Are you using Sweet Candy and/or Bud Explosion? More K heavy shit, and I'm seeing more and more problems with this,... they have changed the formulation AGAIN this May, BTW,.. tells you something, right? 3-4th time now....
I think you have B and/or Mn locking out from antagonistic uptake issues,... I'd flush the fuck out of the coco, and start cutting that monster 300ppm tap with RO/Di water, too much CaCO3 will screw with pH after a while, bad news in coco that wants to be around 6.0...
recommendations I see for flsuh: ro/Di water with 150ppm Ca-Mg, plus 150ppm nutes (base), pH 6.0, pour through until r-o is at or near input values... ppm's have been too high in any case, get the water base ppm down to about 150, no Ca-Mg/epsoms,... most folks run MC at about 450-600ppm (nute only)..

 

[MesaBoogie]

Are you adding calmag in veg?

I haven't used calmag at all in veg and they don't seem to have issues until they start to flower.

 

[MesaBoogie]

MC has plenty of Ca-Mg in it alone, more is making matters worse,... epsoms an overkill! ....Are you using Sweet Candy and/or Bud Explosion?

Yup, I totally noticed that with adding extra calmag made matters worse. So I thought I may have been locking out the MG so I went the other way and just added Epsom salts.. Again, making matters worse. I dont have sweet candy or bud explosion. However i do add Big Bud and it doesn't seem to exacerbate the problem.

I'd flush the fuck out of the coco, and start cutting that monster 300ppm tap with RO/Di water

Long term RO/Di water isn't going to be a very viable option for me. Do you think switching up nutrients may solve the issue or is the "root" cause more likely the hard water ?

(edit) just a bit of an afterthought, we are going to start testing that opticfoliar soon, think that will kick this problem in the ass ?

 

[Mizzo81]

Starting with 300ppm water doesn’t help either as u don’t know what’s in the water. I would run into similar issues when using my well water also over 300ppm. RO water has solved my issues.

 

[Olderfart]

+1 on too hard water. I went to lake and creek water, and it seemed to work better than my tap water which was over 150ppm. CocoforCannabis dot com discusses this and warns about the problem. For most EC/PPM meters, that website suggests that water over 300EC (150PPM for most meters) is a bad idea. If you haven't been on the site, it has a lot of great information on growing in coco.

 

[Waira]

You need to flush Mesa', it's the only way to be rid of the excess nute salts build-up,... coco is a bitch to deal with, it's not "soil", and doesn't have the flexibility that true soil has... fight with it, and it fights back, and the plant suffers!
Do you have sefl-fill water machines around? Those put out excellent low ppm water for relatively cheap...

 

[MesaBoogie]

Do you have sefl-fill water machines around?

Unfortunately no. We can pick up 5gal jug of bottled water for about $7. That will get kind of pricy and it will be a bit of a problem with hauling and working with it long term.. The hands arn't what they used to be ! My next option I suppose will have to be RO. It's not in the budget right now, but maybe soon.

I did give it a good flush 2 days ago with a low dose of nutes and calmag. I got the runoff ppm down to 500. But as I'm sure you guys know already, using that same hard water it didn't help at all. It actually seemed to progress even harder.

So I may be stuck with the problem until I can get a RO system. I would dump the coco going forward but I just cant now after doing a few grows with it. Ugly leaves or not, it produces big fatty plants and no over water f'ups. Wish the plants would stop being so pissy these first few weeks of flower.


And thank you guys for your feed back and taking the time. You guys rock !

 

[MesaBoogie]

So my plant above really turned to the ugly side.. But that's ok, I'm moving on. Ugly leaves or not they still produce good smoke.
I found 2 volunteers in my tent that will be starting their flowering soon that I can experiment on with bottled water. I've done enough plant cycles to know that for sure the spots are going to come during early flower. So I'm doing this for anyone searching this issue in the future can look at see the results of changing from hard water.

My 2 test subject, Strawberry Nuggets left and Sweet CBD to the right.. I'm guessing they should be starting their stretch/flower soon.

I'll post a couple updates in a week or 2...