does this look like Mag?

[seek_UP]

Hello all,

You are looking at 2 G13xNYCD ladies (h3ad seeds) vegging under one 600 HPS (24/0). Recirc DWC, rez temp is kept at 60F with chiller, PH is kept under 6 (using pirhana so the PH climbs daily to 6.3 to 6.5). Air temp is 85F day, 72 night.

Nutes:
tap starts at 260
1 tsp pirhana/gal
10ml hydrogaurd/gal
10 ml sweet/gal
topped with PBP grow to 1300 PPM.

Plants were just moved over HPS 1 week ago and were sitting at 1500+ppm while under floros.

Girls started showing yellowing on the top leaves starting at the leaf base (where connects to stem). Yellowing has since progressed to the outer edge of the leaves (As seen in pics). Does this look like Mag?

pics with HPS on:






And with lights off and camera flash:







thanks all,

 

[sproutco]

Looks like zinc deficiency. Too much magnesium, iron, copper,...can cause a deficiency. Phosphorus excess especially. Low temps in the root zone and high ph don't help. Are your roots ok?


This plant looks similar to yours Click on it to enlarge

1. bleached areas but along the leaf margin stays green
2. wavy margins; your plant does not have this as much is twisting a little
3. no burned edges at tips = not calcium deficiency

Your plant in some of the leaves looks more like the picture in the complete guide to sick plants by mynamestitch that is a sticky in this forum.



If I were to guess, its the sweet containing alot of magnesium causing a "lockout" of zinc. Doesn't it contain alot of iron too?

 

[seek_UP]

thanks sprutco,

That makes sense as my tap water (250-270 ppm) probably has significant mag in it. I'll try swapping the nutes and ommiting the sweet from the lineup (stuff is expensive anyway).

Once the problem is corrected, do the effected leaves recover from zinc deff?

 

[sproutco]

Check your label: Sweet 10 ml per gallon of water adds 2.27 ppm iron and 50 ppm magnesium. That's alot. Plus, I am sure pbp grow has magnesium and iron. Affected areas that are bleached may not revert back to green. Yellowed areas may regreen with added zinc. A foliar spray of a fungicide containing zinc like zineb would work. Also a spray of 56 ppm zinc derived from zinc sulfate could be used. See directions on how ppm's work in my signature how to make your own nutrient solution. If you dont have a gram scale maybe you can come up with a teaspoon rate. You want need much. You could raise the level of zinc in the nutrients something llike .2 ppm's contantly derived from a zinc chelate like edta zinc. Last option is to eliminate competition from other elements and hope there is enough zinc in your pbp grow. This is a problem with pecan trees. You hate a bad nut.

 

[sproutco]

Overgrow cached page:

Zinc
A Zinc deficient plant is obvious from the wispy new growth with twisted leaflets at 90°. There is also intervenial chlorosis at the top of the plant that is commonly confused with an Iron deficiency

http://64.233.161.104/search?q=cach...abis+zinc+deficiency&hl=en&gl=us&ct=clnk&cd=2

I put arrows on his leaves twisting 90 degrees. Very interesting and distinct. Take a look. Click on it to enlarge.

Pretty neat how they twist, huh?

 

[seek_UP]

Sprutco,

I agree, based on that description, it's dead on Zinc. The only thing thats wired, these had pretty much the same mix of nutes (except for a bit more PBP grow) under the floros and they didn't show this.

Maybe the added stress of more intese light helped bring out the deff??? I'll change the nutes and report back... thanks a ton!

 

[sproutco]

I bet your source water contains alot of calcium at 260ppm to start. What is it?

The zn of the zn edta complex is completely replaced by calcium at higher ph values.

I would try lowering your ph even with using chelated zinc. Iron, manganese, copper can inhibit uptake of zinc. Alkaline earth metals also inhibit uptake with magnesium > calcium. Switch to distilled or reverse osmosis water to be exact in knowing what your water is doing. You can get your source tap water tested for a few dollars to find out what is in it exactly. You could make your own nutes to exclude adding calcium for example if enough is in the tap water to start. You might try raising root temperature slightly.

Looks like the light should be aboout 12"-24" from the tops according to this hps chart. http://www.icmag.com/ic/gallery/showphoto.php?photo=150896&sort=1&cat=500&page=1
I would say it could be light bleaching but your leaves are getting that 90 degree twist. Here is a light bleached plant. Click on it to enlarge.


Zinc and light bleaching? Raise the light some to be sure and change the nutes like cut the sweet in half to 5ml. Too much magnesium anyway probably. 10ml per gallon of water sweet was 50ppm magnesium + pbp grow's mag. Only need about 50 anyway.

Here is a nutrient profile list for mj at different stages of growth. Along with it at the bottom of the page is a calculator. http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm You enter the pbp grow net weight of the bottle, ml used, and % element like 5% calcium into it. It will give you the ppm's of each element like 200ppm nitrogen. Compare your rate to what is suggested for your stage of growth. This info may already be provided on the bottle or on their website without having to do the calculator thing.

What would be cool would be to take some pictures of just the leaves that clearly show a 90 degree twist or wavy margin.

 

[sproutco]

Here is some suggestions if your using pbp bloom for flowering. You can get a feel for how you might tinker with the pbp grow formula.

Here is PureBlendPro Bloom @ 15ml/gal [parts per million]
129 n
45 p
214 k
26 mg

If you are aiming for this in bloom according to Mel Frank's suggestions and basically the lucas formula: [parts per million]

100 n
100 p
200 k
60 mg

You can see you need to add more phosphorus (p) and magnesium (mg). If you raise the level of magnesium, you should also raise the level of calcium (ca). So you need that too. You cant raise the level of cal mag in the pureblend pro with cal mag plus because it contains nitrogen. You can see you don't need more nitrogen.

PBPBloom 15 ml per gallon, plus 5 ml cal mag per gallon(GrowGreen's formula) it resembles the grow formula of FloraNova @8ml, as well as GH's 15Grow, 10Micro, 5 bloom formulations, the most copied recipe Ive found. It seems competition only copied GH's veg formula for the most part..[parts per million]
161 n
45 p
214 k
45 mg

Try to achieve 4:2:1 potassium (k):calcium (ca):magnesium(mg) in your water.

>>>1/4 teaspoon (1.25ml) powdered gypsum per gallon of water (3.8L)=70 ppm calcium

>>>1/4 teaspoon (1.25ml) espom salts per gallon of water (3.8L)= 30 ppm magnesium

>>>1/4 teaspoon (1.25ml) monopotassium phosphate (KH2PO4) per gallon (3.8L) of water = 73 ppm phosphorus and 88 ppm potassium

The epsom salts and gypsum would not add nitrogen. To figure how much calcium is in pbp bloom, use this calculator if needed which requires net weight, % elements like 5%calcium, and ml used. SEE LINK IN PREVIOUS POST. The information may already be on the bottle. Remember the 4:2:1 ratio when adding the cal mag. You now need a source of phosphorus to increase it 55ppm or so to 100 ppm. Something with monopotassium phosphate (added potassium with phosphorus) would work. If you get the salt in its plain form, you can weigh it with a gram scale following the directions of making your own nute solution in my signature or use the handy teaspoon rate above. Its okay to raise k to 300 ppm rather than 200 ppm. Remember 4:2:1 ratio again. Don't get your mag over 70 or 80. Calcium may have to be raised to 1.5:1 potassium to calcium instead of 2:1. Calcium to magnesium might need to be raised from 2:1 to 3:1. This might require experimentation on your part with your growing conditions.

Ph should always be checked and adjusted when needed. Directions for making your own ph up and down are in my signature below.

 

[sproutco]

PH is kept under 6 (using pirhana so the PH climbs daily to 6.3 to 6.5).

Last comment. Are you using phosphoric acid daily to get the ph straight? This could be the source of the zinc problem if this deficiency is what you got. See my signature for making your own ph up and down for alternatives to this that won't cause problems.

120 views and no one else wants to comment. Does all this sound right?

 

[seek_UP]

Sprutco,

Thanks for the detailed response. I think it makes sense, but let me clarify the following:

1. I'm using GH ph down (orange stuff), not sure right now whats its made of.

2. I calibrated my ph meter last night and found out it was reading about 5 points too high (it was reading 6.3 when it was actually 5.8). This may have been part of the issue as the ph would rise to what I thought was 6.5 or so, I would lower it to 5.2 in order to allow it to raise back to around 5.8. In retrospect, I was lowering it to 4.7

Maybe this contributed to some lockout.

3. I don't think this is light bleaching, I've seen that before and it kind of looks like the green is just literally peeled off. That's not what this current condition looks like.

I like the calculator, I will run everything through to see approximately where I'm at on the ratios...

Here's another thing that may be of interest in diagnosing this, the plant that shows a bit more of the deff has a noticably smaller root system than the other plant which only shows this condition on 1 or 2 leaves..

Sprutco, what do you think is an ideal nutrient temp?

 

[sproutco]

Sprutco,

Thanks for the detailed response. I think it makes sense, but let me clarify the following:

1. I'm using GH ph down (orange stuff), not sure right now whats its made of.

2. I calibrated my ph meter last night and found out it was reading about 5 points too high (it was reading 6.3 when it was actually 5.8). This may have been part of the issue as the ph would rise to what I thought was 6.5 or so, I would lower it to 5.2 in order to allow it to raise back to around 5.8. In retrospect, I was lowering it to 4.7

Maybe this contributed to some lockout.

3. I don't think this is light bleaching, I've seen that before and it kind of looks like the green is just literally peeled off. That's not what this current condition looks like.

I like the calculator, I will run everything through to see approximately where I'm at on the ratios...

Here's another thing that may be of interest in diagnosing this, the plant that shows a bit more of the deff has a noticably smaller root system than the other plant which only shows this condition on 1 or 2 leaves..

Sprutco, what do you think is an ideal nutrient temp?

General hydro ph down when I checked their website said phosphoric acid. If you remember before I stated phosphorus and zinc compete alot. So if your adding alot of phosphoric acid this might cause problems. Consider switching to sulfuric acid. Directions for making your own ph down with this are in my signature below. Interestingly zinc deficiency is related to root growth. It occurs often in cool temperatures because of reduced root growth outdoors. So this might match up with what is going on with fewer roots. 68 degrees seems warm enough for the roots. IMHO I would not have it lower. Trying to figure out a deficiency or something odd like this is tricky. Getting your nutrients exactly figured out is important. It takes guessing out of it. Low ph may have made competition from iron, manganese, etc..higher with zinc because they became more available at a lower ph. Be sure to read everything I wrote.

 

[seek_UP]

sprutco,

i definetely read all your posts, and also the site you linked to with the calculator. I have that now and will plug in all the numbers this weekend to see how close (or far) I am from the Lucas formula ratios. That's really interesting and I'm surprised I haven;t ran across that calc before! Good find..

On a semi-unrelated note, I was browsing through the compilation of scrog threads on the Cannastats site and people are saying to flip to 12/12 when the screen is 25% full I thought I had read to let it fill approximately 60%, then flip (i've never tried scrog before).

Any thoughts on this? Mine are filling about 50% of the screen at this point and my goal is obviously for them to fill the whole screen with stretch.. Would you flip now or let them veg a bit more??

Thanks again dude for all the help.. It's nice to have an opinion on issues that are actually backed up by supporting docs.. you're an asset to the site for sure..

 

[sproutco]

Thats great your going to try the calculator for your nutrients. Some of the nutes like pbp bloom are partially figured out so you can check your math and inputs. http://www.icmag.com/ic/showthread.php?t=21119 I have done regular plants and sog only. Don't know what to tell you about scrog. Seems like a pain in the ass if you ask me. Training, right?

 

[MynameStitch]

ya thats the start of a zinc problem alright, what nutrients are you using? first time ever seen zinc issues in hydro!!!

 

[seek_UP]

Stich - I'm using PBP Grow, Botan. Sweet, Hydroguard, and AN Pirhana at the time of those pics..

Sprutco - I added the info for each the nutes in use to the spreadsheet calc and came up with the following ppms for the mix I was using at the time this thread was started:

N - 159
P - 35
K - 179
Mg - 66
Cal - 53
Fe - 1.59

I swapped the nutes and have flipped to 12/12 (gotta stay on schedule...). The nutes as of now are as follows:

Tap - 260
8 ml/gal PBP Grow
8 ml/gal PDP Bloom
15 ml/gal Hydroguard
10 ml/gal Liquid Karma

Based on the spreadsheet calc, that roughly equals the following ppm:

N - 143
P - 44
K - 202
Mg - 21
Ca - 42

Here's some pics, it seems the Zinc deff has progressed as the second plant shows the yellowing leaves and both plants now show the wavy edges and brown spots on the tips of outer edges (wavy leaves with brown edge tips are not on upper most leaves, mostly on middle leaves).

 

[sproutco]

I swapped the nutes and have flipped to 12/12 (gotta stay on schedule...). The nutes as of now are as follows:

Tap - 260
8 ml/gal PBP Grow
8 ml/gal PDP Bloom
15 ml/gal Hydroguard
10 ml/gal Liquid Karma

Based on the spreadsheet calc, that roughly equals the following ppm:

N - 143
P - 44
K - 202
Mg - 21
Ca - 42

You want a 4:2:1 ratio of potassium to calcium to magnesium. Normal range for magnesium is 30-50 ppm. You have 21 so add 5ml sweet per gallon 21+25=46 ppm total magnesium now. You need 100 calcium to be in the ratio. You have 42. 1/4 teaspoon powdered gypsum per gallon of water = 70ppm calcium. 42+70 = 112. So you should add that also. You want 100 nitrogen so your current mix with 143 has alot of nitrogen. You should maybe look into just using the pbp bloom without the grow. Directions for tinkering with this I posted previously.

0-0-0
Application Rate
10ml of Sweet per gallon of water will achieve 50ppm Magnesium(Mg), 75ppm Sulfer (S), 2ppm Iron (Fe).
Guaranteed Minimum Analysis
Total Nitrogen (N) 0.0%
0.0% Water Soluble Nitrogen
Available Phosphate (P2O5) 0.0%
Soluble Potash (K2O) 0.0%
Magnesium (Mg) 1.5%
Sulfer (S) 2.00%
Iron (Fe) 0.06%
Derived From: Epsom Salt, Ferrous Sulfate
Non-Plant Food Ingredients: Cane Sugar

So... 10ml/Gal will Yield
N 0
P 0
K 0
Mg 50
Ca 0
S 75
Fe 0
Si 0
+Trace Elements

Looks like your getting more than 1 deficiency now. Calcium deficiency? Look at the edges and tips burning. Compare to this plant:


This may be because you had alot magnesium, needed a little more potassium, and definately needed alot more calcium. You had more magnesium than calcium. Remember the 4:2:1 ratio of k ca mg.

To be sure your nutrient solution works out just right, you should invest a few dollars on good water. There is a water purifiying place in my town that will sell you water and fill up your own jugs. Cost very little. A r/o system would be great. Distilled or purified water from a grocery store would be really good but will end up being costly in the long run. Maybe give pure water a shot and see what results you get with a better ratio of elements.

 

[seek_UP]

I'm thinking this has to be some kind of lock-out. Will start a quick 1 day flush and see if things straighten up. its wierd that no problems until moved under HPS The only things that have changed are colder water temp (now using chiller) and more light. Moved the light up a bit to 24" from top of net..

grrrrrrr................

 

[sproutco]

Don't let your water temp get below 68 degrees (19c)

 

[seek_UP]

sproutco, mine was sitting at between 60 and 62 when this all happened (I've since raised in to range between 62 and 64). Can this low of a temp cause lock-out???

Stupid POT-tv, i saw on their where a guy said 58f was the perfect res temp

also, how do I give good rep? I want to add to your rep but I'm not sure how..

 

[sproutco]

Fix the nutrition problems and raise temps to 68 degrees in the water. Be sure to add fungal prevention like hydrogen peroxide, hydrogaurd, or sm90.