seems like a mag def, but not sure why...

[NZGROWN]

How long has this problem been going on? couple of weeks
Are you growing in a PVC grow tent? (example: Hydrohut or any other non brand tents) no
What system are you running? (DWC? Ebb flow? Aero? Water Farm? Flood Tables? and so on...) ebb flow
What STRAIN are you growing? NL5
What was the establishing technique? (Were the seed or clone?) clone
What is the age of your plants? 4 weeks from clone
How long have they been in there mixture they are in now?(coco,soiless etc..) 3 weeks
How tall are the plants? 30cm
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? veg
What Technique are you using?
What substrate/medium are you using?(Hydroton, RockWool etc.) hydroton
What is the Water temperature? 22c
What color are your roots? White? Brown? Are your roots slimy? white
What Nutrient's are you using?(If growing soiless) Canna Aqua
How much of each nutrient are you using with how much water? EC is 1.6 in 200l reservoir
How often are you feeding? (If using soiless) every 6 hours
How often are you giving nutrients? (If using soiless) every 6 hours, lights on 24/7
If flowering, when did you switch over to using Bloom nutrients?
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) only using veg nutes
What is the TDS/EC/PPM you are using? 1.6
What is the pH of the "Tank"? ranges between 5.8-6.4
Are you sure your calibration is correct on your equiptment? yes
When was your last watering? 5 hours ago
What is your water temps? 22c
When was your last feeding change? (ie. grow-bloom-micro-additional)
How often do you clean your system: example: Flush out water replace with clean water and nutrients? every 2 weeks
What size bulb are you using? 2x600hps
What is the distance to the canopy? 50cm
What is your RH Factor(Relative Humidity)? 30-40%
What is the canopy temperature? 25c
What is the Day/Night Temp? (Include flucutaion range) lights on permanently
What is the current Air Flow? (cfm etc.) plentiful
Tell us about your ventilation, intake exhaust and when its running and not running ? exhaust is a 150mm centrifugal fan with carbon filter, intake is massive, 60x60cm fine filter
Is the fan blowing directly at plants? yes
Is your water HARD or SOFT? soft
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? tap water
Are you using water from a water softener? no
Has plant been recently pruned, cloned off of or pinched? no
Have any pest chemicals been used? If so, What and When? no
Are plant's infected with pest's? no


Hey guys, I've been growing in soil for years, this is my first attempt at hydro. I feel like i've got everything within correct ranges, but cant shake what seeems to be a mag def. any ideas? most of the side shoots are perfectly green, but then the big fan leaves have interveinal yellowing and older fan leaf edges are getting some pretty bad chlorosis going on. Any advice will be greatly appreciated, cheers!

 

[10k]

If you would lower your input pH range (do it gradually) to something around 5.3'ish and not allow it to drift up much past 6, you will see them greening up considerably. The start range of 5.8 is a horrible input range in chem hydro and is the absolute weakest point for mg availability. P and some of the micros drop off when your chem hydro salts drift up past 6'ish especially def when it's running up past 6.4

Somewhere here on icmag and elsewhere on the net is a very misleading square bar chart style pH chart which is advising the input pH of 5.8.
The chart is total misinformation when dealing with chem hydro salts type nutrients, and should be thrown away as useless imnsho.

hth,
10k

 

[oregon bob]

I'm havin a hard time differentiating the colors on 2, 3 & 4... almost as if the gloss is throwing me off, but they look like they are a lighter yellow up top, towards the outsides of the leaf fingers...? Pic 4 throws me a little as all look light green exc wnd from left, up top, which holds the yellowing. Is this correct? Is there what appears a reddish hued (perhaps rusty) coloring between the veins? I dont see any rust spotting, correct?

The reason is it seems like K def developing, esp if the leaf edges are raising, as it appears in pic 2,3,4, at varying spots. the odd leaf growth of pic 4 is also consistent with my babies. Pic 2/3 clearly shows the purpling of stems for your K and/or P. The photo colors are off to me for some reason... couple more w the flash perhaps...?

They seem hungry for the macros, but this isn't likely your ppms as this could even be considered high for the size of plants. The pH is high, for sure. Would recommend running 5.5 (no lower than 5.3) to 5.8 (no higher than 6.0). This may be interfering with the uptake.

I'm not in clay, but it seems to me every 6 hours is a bit long between cycles... it dries out fast. If you dig around a little, is the root mass well established? Any light browning (drying)? You may want to bump the rates & check your run-off (catch some before it returns to the main rez) & see the pH/ppms. The pH may be off along with higher ppms... esp if it is drying too much.

Simple solution is to flush a lot, drain 2 waste. Would recommend running 700ppm & pH 5.8 until the run-off corresponds. This will get the medium correct with the solution. Wasteful, but will correct.

Best brah & doesn't look that far from right! EDIT= there goes my pH rec of 5.8... go his 5.3, maybe 5.5... ;-)

 

[bitpoop21]

its probably the grow rocks what did you clean them with?
I would flush the grow rocks with 25% nutrients.
try the bubbler system 5 gal buckets with net pots and an air stone.
I had ph go from 5 to 7 with no problems.

 

[bitpoop21]

did it happen right after you put them in with all of them grow rocks?

 

[HeadyPete]

PH and too much food. They are mighty green and clawed down. What's the ppm on that tap water?

 

[NZGROWN]

FARK! Just typed out responses to all of you kind people, then pressed delete and went back a page and lost it all, GRRRRRR.

Quick non-personalised version:

I lowered Ph(thanks 10k and O.B.), looking better. Have been spraying with weak solution of epsom salts also.
Now facing what looks to be a K def (good spotting O.B.) I'm thinking it's due to some really low humidity - a constant 25%. Working on raising humidity, by running cooltubes to lower room temp.
Also dug down to find some roots browning, half increased watering to every 4 hours.
Won't be throwing all my gear out for a DWC system just yet, thanks bitpoop21. I rinsed all my clayballs with Ph'd water prior to use.
And headypete, My tap water is ec 0.2. Here's a story for ya: I took some photo's down to the hydro store, the guy was like "what ec are you running?" I said "1.2", to which he replies "Na, crank it right up, get them thriving in some 2.2, they'll love it, I've had plants in 3.6 just loving it" So I went home and quite unwillingly raised my ec to 1.8. I was expecting someone here to pick up the particularly high ec for this early stage. When I flush and change nutes tomorrow, I'll come back with a slightly lower ec. Don't think I'll read too much into what the hydro guy tells me anymore.

Thanks all for your thought out responses! I'll bring more pics to the ball game when my scrog fills a lil

 

[NZGROWN]

Coming along nicely....

Coming along nicely....

Thanks again team, you helped me out of a tight spot and now I can't keep up with the growth rate! Cheeers!

 

[Citizen024]

Great recovery!

Great recovery!

Sweet!! Got to the end and saw your new pics- righteous!

Wanted to chime in one last bit- changing your res every two weeks can sometimes be a stretch. t depends on your res size- a really big one can make it, but the really explosive growth rate may start to decline over the last 3-7 days if the tank is getting used up. Plus your K def probably has something to do with it. Would recommend every 7 days to keep it more balanced and even. Plus the plants don't eat nutri's evenly, so the composition may get off (creating deficient or sometimes even lock out). It will also contribute to ph shift as the salt balance changes. Your corrections can then start to really effect the nutrient compostion more as well. It can become a viscous circle. The rocks evap a lot too, especially if your at 25% rh, your air will be sucking it dry all the time- once again tampering with your chemistry composition. You will need to add water to keep your tank near its original level, and watch the nutrient concentration. This will further alter your chemistry (read on). You may need to add a boost of Cal-Mag (30-50ppm- sorry no ec# replenishes cal,mag, iron, and some N) or epsom after a bit (I do mine at 3-4 days) as your babies suck it down too.

A comment on water: Your nutrients are also going to have to deal/react with the minerals in your water. This can through hydro formulas off sometimes, locking out valuable nutrients as they react with the water. I know Canna says they are formulated for hard water (and their nutrients are top notch no doubt)- but there is no predicting just what and how much is in your water. Most hydro nutrients are formulated to work best in RO unless otherwise indicated. Your water is "soft" so it sounds much better then most- but most tap water is generally fairly hard and calciumed even if the ec is low. They do it on purpose cause it keeps pipes from rusting.

Any res top off's you do will also add more minerals, since the ones you put in from the original fill are still there. I have even seen ec go up as people add tap water trying to bring it down- caught in a water loss mineral build up. This pretty much trashes your chemistry. Personally- I have given up recircing tap water with hydro nutrients. RO is so much cleaner too. Our ph corrections cause the minerals (primarily the calcium) to fall out and percipitate onto EVERYTHING. Especially in rocks, where evap will then cause it really to scale quickly. Over time the lime scale gets really bad in your hoses, pumps, etc. Use CLR between cycles to get it out. Soak your rocks in it too, rinse well when done.

 

[NZGROWN]

Cheers Citizen! Re: 1st paragraph, my reservoir is huge compared to my table, 300 litres home made and I fill it to 200 litres (50 gallons -ish). With the table fully flooded, There's usually about 100 litres left in the res. This excess helps keep Ph in check pretty nicely now that I've got it right. It also means I should realistically get 2 weeks between changes, fingers crossed. Just tonight I did my first ever complete res change and flush, after just surviving on top ups for the first 4 weeks of my grow -eeek! Will endeavour to keep on top of things a bit better from now on.

Cheers for all the additional info, always nice to have tailored advice. NZGROWN.

 

[BigGreen]

So what did you do? Did you run your ph to 5.3 then let it drift to 6.0 thats it. They look really healthy now good job on em.

 

[NZGROWN]

Yeah BigGreen, thats exactly what I did. I just try to catch 'em at 6-6.2 and bring em back down to 5.2ish. They're coming along quickly now, wont be long until I flick them on to 12/12

 

[BigGreen]

Thanks. Im having similar issues right now and Ive been bringing it back down to 5.2 for about a week and its slowly getting better.