Assistance required, toxicity?

[BCrocker]

Test the pH of your water first, and take a temperature reading along with it if you can (water temp). Then do the medium test and get back to me.

Just to make sure:
Do you want me to check the pH and temperature of my water, after filtration, before any nutrients are added? We are currently using an RO system.

The thing that shocks me about all of this, is that I/we have duplicated the scenario of another ass best as possible.

I will have this tested first thing in the morning

 

[LexLuthor]

What do you mean by 'duplicating the scenario of another as best as possible'??

If the pH coming out is 5.9 and you put it in at 5.8-6.0, then I don't think the issue is pH. If you got all the other factors, like EC, temps, RH, ect. at optimal levels then check the root zone because fungus issues could look the same as over-fert, under-fert, pH issues, ect. A fungus/mold/mildew issue could also come from the air, like kamikaze's, so that could be another avenue for ya'll to inspect.

Sorry I can't help anymore, I really hope ya'll figure this out and fix the issue soon, good luck.

 

[BCrocker]

What do you mean by 'duplicating the scenario of another as best as possible'??

If the pH coming out is 5.9 and you put it in at 5.8-6.0, then I don't think the issue is pH. If you got all the other factors, like EC, temps, RH, ect. at optimal levels then check the root zone because fungus issues could look the same as over-fert, under-fert, pH issues, ect. A fungus/mold/mildew issue could also come from the air, like kamikaze's, so that could be another avenue for ya'll to inspect.

Sorry I can't help anymore, I really hope ya'll figure this out and fix the issue soon, good luck.

By duplicating I mean we made everything the exact same as another location. Bulbs, fans, ballasts, nutrients, pot size, coco, perlite, etc.

I have noticed some algae below a few pots and a few pieces of perlite were green. I thought this might be from watering too often. Although, these are done every other day at most. Haven't noticed any mildew, we sprayed eagle20 early in veg and haven't seen anything since.

 

[BCrocker]

Here are some leaf shots. Random plants, through room. Only a few leaves like this through the entire room. (96 - 10 gallon pots)

 

[We Solidarity]

what nutrient are you using? and how close are your lights?

 

[cctt]

What is the runoff EC?

 

[BCrocker]

OK the pH test with distilled water came out at 6.2 for the week 5 room. Another one shows at 6.0

The terribad week 8 room came out at 5.7

Nutrients are being put in at 5.8

Canna nutrients

 

[squiggly]

OK the pH test with distilled water came out at 6.2 for the week 5 room. Another one shows at 6.0

The terribad week 8 room came out at 5.7

Nutrients are being put in at 5.8

Canna nutrients

I think 5.8 might be a bit low for that late in flower.

Correct me if I'm wrong someone, but ideally we'd like to see the pH drifting up as flowering progresses.

So

Wk1: 5.8

Wk2: 5.9

Wk3: 6.0

etc.

Of course this isn't a "bible" it's a guide. You should adjust your pH based on what nutrient deficiencies you see and what's going on in your medium.

 

[BCrocker]

Make adjustment to pH of nutrients going in then?

 

[squiggly]

Make adjustment to pH of nutrients going in then?

Yup, but do it gradually--don't be crazy.

 

[LexLuthor]

I've seen people say let the pH go down as flowering progresses to allow higher P uptake, because P is more available at a lower pH. I've also seen people say let it go slightly higher, but I don't know why.

 

[squiggly]

I've seen people say let the pH go down as flowering progresses to allow higher P uptake, because P is more available at a lower pH. I've also seen people say let it go slightly higher, but I don't know why.

Yes I have heard that as well.

I am actually speaking from experience on this one. I usually only go up to 6.1pH in my soil.

I don't really care where its at as long as it's between 5.7 and 6.1.

What I will say as far as "common knowledge" on P uptake is that it's mostly shit. The truth is that P uptake really is the limiting factor in most plant growth and it's not something that is understood very well.

In mycorrhizal species it is very scarcely understood--and in cannabis among them even less.

it is unknown if there are multiple phosphate transporters. phosphoric acid is a polyprotic acid which means that it can lose more than one hydrogen ion to solution--it does so in a step wise fashion at various pH thresholds. So really we're in the dark here.

The general case says you want to be between 5.0 and 6.0 for optimum phosphate uptake if I remember correctly.

 

[BCrocker]

OK well as it seems the pH is fine in this situation. Could this possibly be heat stress effecting nutrient uptake?

 

[LexLuthor]

OK well as it seems the pH is fine in this situation. Could this possibly be heat stress effecting nutrient uptake?

Do you know the actual profile of the nutrients you are using?? It could be something thats too high and locking out others. Just a thought.

 

[BCrocker]

I'm not sure of the actual nutrient profile for canna coco A+B and their PK. I will try and figure it out, although this works in another location perfectly without issue! same nutrients, same clones even.

 

[LexLuthor]

I'm not sure of the actual nutrient profile for canna coco A+B and their PK. I will try and figure it out, although this works in another location perfectly without issue! same nutrients, same clones even.

Oh yeah, you said you replicated in a different location, thats what made me think of fungus or mold before.

You could go to cannastats.com and use there nutrient calculator, its easy.