Continuing Mg deficiency - WTF, still looking for the simple solution

[grapeman]

HYDROPONICS:

What STRAIN are you growing? DP Power Plant
What was the establishing technique? (Were the seed or clone?) Seed to clone
What is the age of your plants? 6 weeks
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? 2nd week of flower
What Technique are you using? DWC drain to waste non-recurclating
What substrate/medium are you using?(Hydroton, RockWool etc.) Hydroton
What is the Nutrient temperature? 74.7
What Nutrient's are you using? House & Garden Aqua Flakes + additives (inc. 2 mil CalMag/gal)
What is the TDS/EC/PPM you are using? Today EC = 1
What is the pH of the "Tank"? Today - Mix to 5.8 Today In the bucket is 6.2
Are you sure your calibration is correct on your equiptment? YES - no doubt
When was your last watering? DWC with 1.25 watt of air pump/bucket Drain every 5 to 7 days and refill with fresh nutes
When was your last feeding change? (ie. grow-bloom-micro-additional)
What size bulb are you using? 600 w 3x600w (1800 total) over each 4' x 8' platform of 21 buckets
What is the distance to the canopy? 20"
What is your RH Factor? Day = 35% night =50%
What is the canopy temperature? Room = 76 Canopy = 79
What is the Day/Night Temp? (Include flucutaion range) 77/75
What is the current Air Flow? (cfm etc.) Plenty
Is the fan blowing directly at plants? Mildly on the grow with wall mounted fans
Is your water HARD or SOFT? Hard. using RO water with EC >100
Has plant been recently pruned, cloned off of or pinched No
Have any pest chemicals been used? If so, What and When? Floramite prior to move to grow room 4 weeks ago
Are plant's infected with pest's No

 

[grapeman]

Cannot seem to shake this. Appears in about week 3 or 4 in the last 2 grows. Treating bi - weekly with Epsom salt spray and adding cal-mag to the H & G nutes. Ph is correct. Plenty of air in the roots. Water temps are not perfect but close. Can't figure this one out.

 

[DiscoBiscuit]

from the infirmary:


Excessive levels of magnesium in your plants will exhibit a buildup of toxic salts that will kill the leaves and lock out other nutrients like Calcium (Ca). Mg can get locked out by having too much Calcium, Chlorine or ammonium in your soil/water.
One of the worst problems a person can have is a magnesium def caused by a ph lockout. By giving it more magnesium to cure the problem when you are thinking you are doing good, but actually you are doing more harm then good. When the plants can’t take in a nutrient because of the ph being off for that element, the plant will not absorb it but it will be in the soil… therefore causing a buildup. A buildup will be noticed by the outer parts of the plant becoming whitish and or a yellowish color. The tips and part way in on the inner leaves will die and feel like glass. Parts affected by Magnesium deficiency are: space between the veins (Interveinal) of older leaves; may begin around interior perimeter of leaf.


Hydro and Soil less Mediums

Magnesium gets locked out of Hydro and Soil less Mediums at ph levels of 2.0-5.7
Magnesium is absorbed best in Hydro and Soil less Mediums at ph levels of 5.8-9.1
(Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Magnesium deficiency.

 

[grapeman]

Thanks for your comments DB. Unless my 2 PH meters are off along with my PH testing solutions, it is hard for me to believe that I have PH lockout due to PH. Always ph the water/nute change to 5.8 and it slowly rises to 6.4 to 6.6 during the week, then I change again. I did 2 flushes this week. I did use tab water for the flushes though. My tab water has an EC of 160. Do you think I should flush again with RO just in case there is a calcium buildup? Man - if this is due to a calcium salt build up then my RO filter sucks. I cannot get my blue stick to register anything after the H2O passes thru the RO. I do have to clean my pool tiles at the water line, my fountains in the backyard and my shower doors every year so I do know I am starting with high calcium water. But shouldn't using RO that tests out at less the 100 EC be removing the Ca?

BTW - I start at with a PH of 5.7 or 5.8 as that is the recommendation on the H & G label.

Thanks for your input.

from the infirmary:


Excessive levels of magnesium in your plants will exhibit a buildup of toxic salts that will kill the leaves and lock out other nutrients like Calcium (Ca). Mg can get locked out by having too much Calcium, Chlorine or ammonium in your soil/water.
One of the worst problems a person can have is a magnesium def caused by a ph lockout. By giving it more magnesium to cure the problem when you are thinking you are doing good, but actually you are doing more harm then good. When the plants can’t take in a nutrient because of the ph being off for that element, the plant will not absorb it but it will be in the soil… therefore causing a buildup. A buildup will be noticed by the outer parts of the plant becoming whitish and or a yellowish color. The tips and part way in on the inner leaves will die and feel like glass. Parts affected by Magnesium deficiency are: space between the veins (Interveinal) of older leaves; may begin around interior perimeter of leaf.


Hydro and Soil less Mediums

Magnesium gets locked out of Hydro and Soil less Mediums at ph levels of 2.0-5.7
Magnesium is absorbed best in Hydro and Soil less Mediums at ph levels of 5.8-9.1
(Wouldn’t recommend having a ph over 6.5 in hydro and soil less mediums.) Best range for hydro and soil less mediums is 5.0 to 6.0. Anything out of the ranges listed will contribute to a Magnesium deficiency.

 

[DiscoBiscuit]

...I do know I am starting with high calcium water. But shouldn't using RO that tests out at less the 100 EC be removing the Ca?

Depending on the size of your res you might consider an alternative water source (as a test.) Use only water that you're sure isn't calcium heavy. If the problem persists, your original water is probably ok.

 

[EvilTwin]

Hi grapeman,
I've grown a lot of White Widow which is a mg defienct prone plant. My leaves always looked much more dramatically striped (interveinal chlorosis) then what your plants show. Are you sure of that diagnosis? Could be some other deficiency and the fact that your mg treatment isn't working sort-of supports that. Unfortunately I don't have an alternate diagnosis yet...but I'll think on it.
Peace,
ET

PS: A simple addition of MgSO4 always resolved my mg defiency within a week.

 

[mean mr.mustard]

That appears to be a P deficiency, not Mg...

 

[Tokesome]

Are the nutrients you`re using specifically designed for hydroton?

I`ve been having a similar problem using coco/hydroton mix, but with a layer of hydreton pebbles at the bottom of the pots for extra drainage (very bad idea). The main root mass being at the bottom were in the hydroton and the feed was a coco specific nutrient and reacted badly in the bottom part of the root zone where there was no coco.

The result was lock out of mg and they looked very similar to your`s. I treated with flushing, epsom salts etc., which helped stabilise the problem (maybe, dont think the Epsom salts helped as it was a lockout I believe), but never cured it.

If you want to check out the threads I`ve had on this they`re here http://www.icmag.com/ic/showthread.php?t=138214&page=8

and

http://www.icmag.com/ic/showthread.php?t=141009

Have you changed anything in your set up, even something you think would be insignificant, around the time that this problem started?

Tokesome ;-)

 

[grapeman]

TY Mustard - I will look into the P. I have not been giving the full recommended dose of nutes (about 3/5's) so far as I have been worried. My plan tonight on 1/2 the room (21 buckets) is to just go ahead and flush with R/O water PH'd at 5.7 and drain then give the full dose and see what happens. I hope they are just hungry. We'll see, since I have tried all else.

TY Tokesome - I am sure I am using the correct nutes. House & Garden "Aqua Flakes". I was worried about this also some weeks back so I contacted Van Zant's via Humbolt distributors and they confirmed to me that, for my exact set up (DWC non-recirculating drain to waste with air pumps and air diffusors) that Aqua Flakes A & B were the way to go with their nutes.

I am hoping things change for the better in a few days.

 

[barletta]

That looks like Phosphorus. I'm not a hydro guy, and I know shit all about EC readings, but I thought that they supposta be closer to ~2.0 in flower?

 

[grapeman]

Can Fungus Gnats cause these symptoms?

Can Fungus Gnats cause these symptoms?

I do have a few fungus gnats in the grow room. I use yellow traps and I have maybe 15 or 20 on the trap over 3 weeks. I have a few here and there that I see buzzing around, but not what I would call a bad infestation. I am wondering if the larvae, if in the buckets, can cause slow growth and the symptoms in the photo above in the beginning of the thread?

 

[grapeman]

YEAH BARLETTA - I should be at a higher EC at this stage but have been reluctant to increase the rates until I got a handle on this shit. As per Mustard's post above (and your's), I am taking one side to where it should be on the EC at this stage in their cycle at this moment. We'll know soon. Thanks for your input.

 

[barletta]

No problem FWIW, I'm a tightwad with the nutes, and the def's that show for me are N and P. I've fought with fungus gnats, and where they really hurt me was in veg/clone. It seems that the flowering plants are easier to deal with, cause they drink more, and dry faster. A layer of perlite on the tops of all pots is said to be an effective cure for gnats. They combined with the cold to cost me a few months over last winter. I was losing ~80% of my clones. I cleaned up, let the plants run dry for ~a month, and I've just been careful to not to let the pots stay too wet.

 

[EvilTwin]

I do have a few fungus gnats in the grow room. I use yellow traps and I have maybe 15 or 20 on the trap over 3 weeks. I have a few here and there that I see buzzing around, but not what I would call a bad infestation. I am wondering if the larvae, if in the buckets, can cause slow growth and the symptoms in the photo above in the beginning of the thread?

MosquitoDunks are a biological control for the larvae. You just drop one in your res and as it dissolves...the organisms are released. Bacillus Thuriengensis or something like that. Benign to the plants and even works in aquarium water...but death to larvae.
ET

 

[Lorenzo]

i also think it looks more like a P deficiency. stronger feeding should help.

also dwc/bubble buckets are not non-recirc/drain to waste, for future reference...

 

[Tokesome]

I put the sticky yellow traps on top of each plant pot, as the gnats always land on something before crawling around. They always land on the yellow pads if placed on top of the pots, just like a landing strip for the lil buggers!!

When you checked out your nutes, obviously they knew you were using hydroton for the medium, yeah?

Toke

 

[latinomies]

Don't know if this has already been said, but whenever I use H&G nutrients on coco, I also display mg deficiency. Not sure if its something with there nutrients, as I dont use their full range and only their A&B.
I personally think that they dont put enough MG in their A&B to encourage you to use the full range of their nutrients which could correct it. Havent ever tried, I've just switched to Canna A&B which totally removes the deficiency.

 

[VenturaHwy]

Use more nutes.... also the burned tips usually mean water logged roots.

Don't try to fix a nutrient deficiency by adding one nutrient like Mg. Use all of the nutes full strength every time. I've made my own for 25 years or so and just spent the last 2 weeks going over the formula. I make a bloom and a grow.

I see many guess my deficiency threads and most are a waste of time... Double your ec and make sure your roots aren't low on oxygen. I'd go to about 2.5 ec

 

[VenturaHwy]

"What Nutrient's are you using? House & Garden Aqua Flakes + additives (inc. 2 mil CalMag/gal)"

Is this made for hydro's? What's the N-P-K?

 

[EvilTwin]

Don't try to fix a nutrient deficiency by adding one nutrient like Mg.

If the deficiency is only with one nutrient...then what's wrong with just replacing that one nutrient?
ET