Is this magnesium deficiency?

This is my first time growing a sativa dominate plant. It stretched way more than I expected. I'm not sure if this has an effect on my problem at hand.

This seems to have the tale tale signs of magnesium deficiency. Green veins, older leaves affected first, and necrosis starting on the tip of the leaf and progressing around the border.

Royal Queen Seeds - Shining Silver Haze.
100% coco (new from Botanicare this grow)
California LightWorks 440W about 8 inches from the top of the plant (I can't go higher)
Autopot XL (6.6 gallon)
1m x 1m x 2m tent
Seeds germinated on 8/18
Switched to 12/12 lighting on 9/20
Temps are 75-80 degrees Fahrenheit with lights on. 69 degrees with lights off.


My nutrient mix:
10 quarts Tap water, municipal source 150 - 175 ppm tds.
3ml General Hydroponics FloraMicro Hardwater
12ml General Hydroponics FloraMicro
25ml General Hydroponics FloraBloom (22ml during veg)
10ml Hygorzyme.
I adjust pH to 5.8 with General Hydroponics liquid. The mix generally comes out pretty close, so not much is used.

I let the pH creep up to about 6.4 before I correct it back down.


Since this issue, I have:
Flushed the coco as best I can, which isn't very good. I'm not able to move the plant.
I've dumped and refreshed the reservoir twice.The second time, I pHed to 6.2.
I calibrated my pH meter and checked it against test strips. It was a little off, reading pH 7 calibration solution as 7.6.
I've added 20g of epsom salts (dissolved into water before adding to reservoir) to the 12.5 gallon reservoir.

The plant keeps getting worse. I'm afraid I'm going to lose the plant if I don't get this figured out soon.

My thoughts now is too much calcium locking Magnesium out. I got the water report for my tap water, but it doesn't give results for Calcium or Magnesium.

You're over ferting. I don't know where people get this nute lockout idea. most of the time the grower's problem is just over ferting. why are you using two kinds of micro? Do they both have nitrogen? I think that's where you're going wrong, along with the measure of how much you're giving. By that I mean you need a ppm meter to really do this right, if I understand you right, this is a hydro grow essentially. hydro growing without a ppm meter can lead to this problem because the grower doesn't accurately know how many nutrients are in the water. It seems like most grows in hydro use between 500 and 1000 or so, for the entire grow. I wonder if you nute content in the water is too high, or maybe you are cycling too often. I don't know if coco is good for hydro as it probably hangs on to nutes quite a bit. You could probably reduce the cycle time and let the coco dry out more and see what happens. Using the ml or teaspoon measure idea without measureing ppm probably isn't a good idea. Also, 20g of Epsom sounds like a lot. The bloom fert already has mg in it.

I agree with pollack. It looks like its burnt. Its not mag defficiant at all. You must have mag in the micro mix. You said you cant flush the plant properly. Theres a couple ways to get around that problem. The first thing you need is a large drip catcher under the pot. Then water like crazy and suck the runnoff up in a shop vac. Youll need to empty it after your done and leave it open or it will mold and get gross in there but it works. The other thing is prop the plant up in the drip catcher with something that wont rot. Ive used chunks of 2x4 before and they last for a year without rotting. Anyway, this will prevent the plant from sitting in the runoff. When it sits in the runoff it can reabsorb all the nutrients its just gotten flushed out with the runoff, thus causing salt buildup in the root zone. Too many ppms in the root zone will cause burn. So if the runoff can just evaporate when it falls out, or drain to waste, you wont have this problem. Either way, i would drop the ppms for a little while and figure out a way to flush or leach the medium. Even if you have to wait until lights out and work a little later with the door open but the lights off. It wont herm, bit youll be able to prop the plant up higher and figure some way out to flush that thing properly. Also a fush during transition from veg to bloom is always good practice. And read the ppms of the runoff. From reading your post im not sure if you even have a ppm meter, and if you dont, thats precicely why youve burnt your plants. Thats like a carpenter without a tape measure, he will never make the right length cut because he can only guess at what hes doing.

That looks like light stress, on top of what you got going on. That looks like what happens to my moms when they get too close to a cfl, 4 inches will crunch up the leaves like that, 8 inches for LED might be a bit too close.

Magnesium is related to chlorophyl, so if your lacking the newer leaves look lighter green then go crunchy. Your plant doesn't look like that.

I think you need to simplify your formula.

-I would use 6ml Micro 9ml Bloom. Per gallon. If you can use water with lower TDS you literally dont need PH down.

Youre mixing kinda wierd, like 2.5 gallons per batch but it does come out close to the formula listed above. I simplified the math.

1.2ml Micro H
4.8ml Micro
10ml Bloom per gallon, so youre running a 5:10 mix.

I tried to run the numbers at GH, but the calculator isn't working.

-Or change over to MaxiBloom. Its NPK should be similar to the formula above.

-I'm not sure if your plastic autopot is causing problems, for a medium like coco that constantly needs saturation fabric pots seem to work better.

-Do not let your PH get out range with coco.

Just some thoughts..

How is you know your starting PPM but don't state the final PPM of your solution you are feeding? Do you not have a decent EC/PPM meter?

it's interesting.

I have a ppm meter and use it every time I mix nutrients. I forgot to include ppm tds of the nute mix in the original post. The meter was about $15 off amazon, so it may not be a decent one. I measure the ppm after I mix the nutes but before I adjust pH. It is about 800ppm and the pH is usually 5.7 - 6.0 before adjusting. I've been running this nute mix with indica genetics for a while. It usually slightly burns the tips of the leaves.

I based my nutes on h3ad's coco formula which is based on lucas's formula. I don't think links to other forums are welcome here, but it's easy enough to google.

The difference between the two micros is that micro hardwater has less calcium. Both are 5-0-1. Since I'm using tap water with fairly high tds, I mix them. Here is a quote from the manufacturers website about micro hardwater:

Used in place of FloraMicro when your starting water contains over 200 ppm or Calcium above 70ppm. Formulated to compensate for the elevated levels in your base water. For starting water with 30 to 50 ppm of Calcium mix equal parts of FloraMicro and FloraMicro Hardwater for the ideal Micro blend.

Click to expand...

Of course, I'm taking the word of the manufacture of the nutes that I should buy more nutes, so that is suspect...

Here is a link to the nutes. There is a link on each one to show the label. The label shows contents. http://generalhydroponics.com/site/index.php/products/nutrients/flora_series/flora_micro/

The micro nutes dont have magnesium, but the bloom nutes does at 1.5%.

Autopots bottom feed the plant. It floods about 2 inches of the bottom and lets it run dry by the plant soaking it up. After it is dry, the autopot immediately floods again. This isn't adjustable. I also have air stones in the bottom of the pot to keep the water oxygenated.

Sorry about the weird units. Mixing imperial and metric and using 2.5 gallons as a base. I have a 3 gallon bucket that is marked in quarts and my syringes are in cc / ml, so that's what I got use to. I should have simplified those units to make it easier on the people helping me out. My bad.

I'll buy a shop vac tomorrow. I'm not physically able to do much heavy moving and this isn't the sort of thing you can ask for help with.

Do not let your PH get out range with coco

Click to expand...

What range do you suggest?

m0dsi said:

The micro nutes dont have magnesium, but the bloom nutes does at 1.5%.
Autopots bottom feed the plant. It floods about 2 inches of the bottom and lets it run dry by the plant soaking it up. After it is dry, the autopot immediately floods again. This isn't adjustable. I also have air stones in the bottom of the pot to keep the water oxygenated.
Sorry about the weird units. Mixing imperial and metric and using 2.5 gallons as a base. I have a 3 gallon bucket that is marked in quarts and my syringes are in cc / ml, so that's what I got use to. I should have simplified those units to make it easier on the people helping me out. My bad.
I'll buy a shop vac tomorrow. I'm not physically able to do much heavy moving and this isn't the sort of thing you can ask for help with.
What range do you suggest?

Click to expand...

When I used to run flora series, I used to run 5:10 also.. but I always seemed to need a bump of magnesium from epsoms. Even now running Maxibloom or Maxigrow a small bump of magnesium is needed, but you should have seen the need for mag earlier, and should have supplemented then not now. Not sure if i'm saying the obvious here but do not use things like cal-mag. I'm sure a little bump of epsoms might get your plant going in the right direction, I dont think it would hurt it.

I dont agree with using autopots with coco.. the point is to saturate the entire pot and not feed from the bottom, I'm a little fuzzy on the theory but its something to do with ion exchange.. Anways things get wierd on me when I let the coco dry out. Its like you have to treat coco like drain to waste... But hey if thats what you got to work with.. coco should always be wet. If you've used this setup before in coco, i'm confused why it would not work now.

The PH advice comes from a friend that is a master of coco, seriously, he grows some top shelf flowers, and we discussed how his coco grow is done, and he told me very clearly 5.8 with almost no swings in the PH, is the way to go because the way coco acts and I've found this to be true.

I checked on her after the lights came on. It's not a pretty sight. I think she may be lost.

Assuming the 20mg epsoms was too much, I was going to flush the reservoir. I notice little stringy like things floating in it. I tried to take a picture, but it wasn't visible in the picture.

I dumped the reservoir and there was a film of stuff on the bottom. It's not unusual for me to have some salts fall out of the nutes, but this wasn't like that. I disassembled the autopot. The hoses were caked in the stuff and the filter was almost completely blocked. Water would flow, but very very slowly.

I replaced the hose and filter and have cleaned everything else with distilled vinegar then water.

This mysterious stuff has the texture of snot. Gross I know, but it's the closest thing I can think to compare it.

What is this stuff?

Is the plant recoverable?

Could the plant's symptoms be under watering?

I'm running 6:10. 6ml micro 10ml bloom per gallon. Not 5:10. 1.2 + 4.8 = 6

I didn't catch that until now. Perhaps I should reduce the micro.

m0dsi said:

I'm running 6:10. 6ml micro 10ml bloom per gallon. Not 5:10. 1.2 + 4.8 = 6

I didn't catch that until now. Perhaps I should reduce the micro.

Click to expand...

Yeah you're right.. I got retarded there.

the snot is algae, which grows thanks to your water being exposed to light. If you don't see how light is the problem, you still need to check everything for algae build up and try a cleaner water perhaps. maybe distilled or using tap water but boil it and let it cool before using it in the grow. also there are products out there like hydroguard that can help control algae growth.