Name That Deficiency (Please...)

Hey -- almost 4 weeks into flowering and there's something wrong here... I've been thinking potassium deficiency, but it's not getting better with added nutrients. Pictures first, then all the details I can think of:





First, the overall yellowness of the photos is the lights -- homemade panels made from 3000K LED strips. I think they're putting out about 40,000 lux at the canopy. The strain is Nirvana's Maui Wowie, and they're in 7 gallon pots of FFOF mixed with perlite. They didn't get any added nutrients until I started them on 12/12, after about 2 months of veg'ing. Since then I've been feeding with General Organics "Bio Thrive," which is 2-4-4 (N-P-K), I started at 2 tsps per gallon and have recently bumped it to 3 tsps per gallon -- every watering (which is about every 3 days). I'm going to have trouble believing it's a calcium issue, as I have hard water (measured recently at 440 ppm, and the town reports plenty of calcium in the water -- could dig up the details if necessary).

Your opinion very much appreciated -- thanks in advance.

(Neglected to "full size" that 3rd picture... "Edit" button never works anymore... Anyway, there are 3 pictures...)

And for what it's worth they're SCROG'ed -- the framework is buried deep under the canopy and hidden.

@algebraist said: First, the overall yellowness of the photos is the lights
Pics without grow lights using lighting that gives it a normal appearance will be helpful.

It is a clear calcium problem.

Your water is too alkaline and there is likely too much calcium. 150 ppm is ideal.

One way to combat this is by watering with a lot of runoff. More than 25% each watering. It helps to wash away built up salts.

If that doesn't work you may get by with a fertilizer that has no calcium like jacks 20-20-20.

If that doesn't work you need to mix your water with ro water at least 50/50. Maybe more.

MichiganMedGrower said:

It is a clear calcium problem.

Your water is too alkaline and there is likely too much calcium. 150 ppm is ideal.

One way to combat this is by watering with a lot of runoff. More than 25% each watering. It helps to wash away built up salts.

If that doesn't work you may get by with a fertilizer that has no calcium like jacks 20-20-20.

If that doesn't work you need to mix your water with ro water at least 50/50. Maybe more.

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Thanks. The BioThrive I've been using has no calcium (a big factor in how I chose it); I'm going to use distilled water for the next few waterings at least, hopefully I can get it under control. Thanks again for the help.

algebraist said:

Thanks. The BioThrive I've been using has no calcium (a big factor in how I chose it); I'm going to use distilled water for the next few waterings at least, hopefully I can get it under control. Thanks again for the help.

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It is possible there is no available calcium. And the water is not supplying it. If the oyster shell in the soil has been flushed out or just used up.

Has she been in the final pot more than the 2 weeks?

Maybe she just needs calcium. The leaves do show it pretty clearly. The problem with organics is the nutrients are not always broken down and available.

It is hard to say. But easy enough to add a little and see.

Wow -- I interpreted your first reply as saying there was an overabundance of calcium (and figured that could be causing lock out of other nutrients). I'm a little scared to add calcium since I know my water has too much of it, and if that's the problem, I'll just be making it worse.

The plants (there are two) have been in these (7 gallon) pots for about 2 months -- I veg'ed longer than I really wanted to in order to ensure they wouldn't be ready to harvest when I was away on vacation in mid August. So they have about 5 weeks to go.

I water today, and I plan on using distilled water with a light addition of the BioThrive -- 2 tsps per gallon. I haven't been paying much attention to pH; I think the soil adjusts pretty well. But I expect that to be rather acidic and I may ph-up it to somewhere around 6.5.

algebraist said:

Wow -- I interpreted your first reply as saying there was an overabundance of calcium (and figured that could be causing lock out of other nutrients). I'm a little scared to add calcium since I know my water has too much of it, and if that's the problem, I'll just be making it worse.

The plants (there are two) have been in these (7 gallon) pots for about 2 months -- I veg'ed longer than I really wanted to in order to ensure they wouldn't be ready to harvest when I was away on vacation in mid August. So they have about 5 weeks to go.

I water today, and I plan on using distilled water with a light addition of the BioThrive -- 2 tsps per gallon. I haven't been paying much attention to pH; I think the soil adjusts pretty well. But I expect that to be rather acidic and I may ph-up it to somewhere around 6.5.

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looks like its all locked up

I am saying that the calcium in your hard water may not be available to the plants. But my advice is really the same. You need to mix your tap at least half with ro or distilled water. Leach the pots with a gallon or two and then re feed with a balanced moderate mix of complete nutes.

If it is your very hard water locking out and or distilled with no calcium at all you will still keep seeing the deficiency.

You need to read about water and alkalinity in container gardening to understand why.

Thanks, @MichiganMedGrower.

I just watered with plain distilled water, nothing added, enough so that there was some significant runoff. Will water with distilled water and nutrients next time -- I have Botanicare Pure Blend Pro Bloom in addition to the BioThrive (I also have FoxFarm Big Bloom, but that has no nitrogen and is more of a supplement than a nutrient).

Buba Blend said:

pics without grow lights using lighting that gives it a normal appearance will be helpful.

Click to expand...

Here are some pictures with the grow lights dimmed as much as possible, using the flash on the camera, so the color is more accurate:

algebraist said:

Thanks, @MichiganMedGrower.

I just watered with plain distilled water, nothing added, enough so that there was some significant runoff. Will water with distilled water and nutrients next time -- I have Botanicare Pure Blend Pro Bloom in addition to the BioThrive (I also have FoxFarm Big Bloom, but that has no nitrogen and is more of a supplement than a nutrient).



Here are some pictures with the grow lights dimmed as much as possible, using the flash on the camera, so the color is more accurate:


View attachment 3979079 View attachment 3979082 View attachment 3979083 View attachment 3979086

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u r locked out ph way off,u lacking lot more than cal

They are def to fuk, bin em

thumper60 said:

u r locked out ph way off,u lacking lot more than cal

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I am saying the calcium in the too hard water is built up and blocking the roots.

MichiganMedGrower said:

I am saying the calcium in the too hard water is built up and blocking the roots.

Click to expand...

yes called lockout, I bet they hardly drink at all roots arnt working