diagnosis please

[stella]

Here's the basics:
400hps growbox, dwc on 12/12
co2 injected
templs inside 77 mAX
60MIN with about 40%RH
res temp 70
using gh micro and bloom, lucas formula
HOWEVER continue to add about 1.5 t/gal of calmag (when i don't, i see signs of mg diff)
1200-1300 ppm, 6.0-6.1 ph
air cooled 400hps is about 12" from top of largest plant
plants u see are nycd and ppp, with bluecheese flushing..(the big bud'd plant in front)
I grow sea of green, so there are plants with various stages of flowering growth- from 1 week to harvest time.

What i'm experiencing:
Intermittent sprurts of growth (roots and bud formations)
the tops of several plants leaves shoot vertical towards the light
purple stems (not all of them, but visible on leaves and stems)
they look real green, perhaps overfert? I haven't checked the runoff..i'll do that today. i change res once a week. During the week, i add ro water with calmag to keep ppm down to 1250ish
the buds arent getting "fat" kinda long caterpillar looking, but dense nonetheless. i don't know what else to say, take a look at the photos..
thanks a million

 

[EvilTwin]

Hi Stella,
I have to say I'm a little confused by what's going on. You made this statement...

"I grow sea of green, so there are plants with various stages of flowering growth- from 1 week to harvest time."

These phrases seem to evolve over time...but my understanding of SOG is that you grow a bunch of plants that are all the same age.

So you have this mishmash of plants of various ages. Are they all getting fed the same?

Without further info, I'm thinking there's something wrong with your feeding regimen and the plants aren't getting what they need when they need.

Flowering nutrients go through changes as the plant develops. More N during the initial stretch...then less or no N and increased P and K. Then throw a bloom booster in there if desired and a flush at the end. You hinted that they may be getting too much N. Certainly that would slow down or discourage bloom. And the calmag your adding also contains N. If all the plants need is Mg...then Epsom salts is a better choice.
ET

 

[Hydro-Soil]

res temp 70

Definitely lower that if you can. Higher DO levels will help, but getting down to around 65F helps a lot. (They handle higher heat as well, when the roots are cool.)

using gh micro and bloom, lucas formula
HOWEVER continue to add about 1.5 t/gal of calmag (when i don't, i see signs of mg diff)

You don't need any CalMag if you tend the res correctly..... Lucas from Flora, Maxi or FloraNova has plenty of Calcium and Magnesium... as long as you allow the proper pH swing.

1200-1300 ppm, 6.0-6.1 ph

Keeping within this pH range is why you are needing to add the CalMag.


The next grow.... start your res out at 5.2pH and let it slowly rise to 6.0-6.1. It should hit that around day 20 or so... let it hover around 6.1 for approximately a week and then drop it back down to 5.2 and let it rise till you start the flush. By doing this, your plants will have maximum absorption rates for all the elements, as the pH swings. By the time they're putting on the big suck for mag and calcium during bud-set... they'll have already absorbed enough mag and calcium and will be able to easily pull it from reserves. No more yellowing and you won't even have to buy more CalMag!

Stay Safe!

 

[stella]

Evil:
yes, it would seem that the definition of sog has changed. when i first started about 20 yrs ago, i thought it meant that you would have a perpetual harvest- plants movng from cutting to veg, plants moving from veg to flower, flower to harvest...at any given time. So, yes, there are different stages of growth within each chamber.. This way, i harvest about 1 or 2 plants every 2 weeks or so, instead of one big harvest, i get small ones every week.
Hydro- you've helped me in the past- thanks. Will YOUR method work with my "sog" method? if not, do you have any suggestions?
I've noticed if i don't add the calmag, i notice a diffenciency within a week... I thought that i needed to keep the ph on the high side for the mg to be absorbed? I used to grow ebb and flow- with no calmag issues (however i used regular tap) MY tap is real hard, about 300 ppm so im trying lucas with RO, now im in a dwc and seems that with the constant bubbles certain elements might evaporate out?

 

[EvilTwin]

Stella,
So each chamber has it's own reservoir too? My concern was that you wouldn't be able to tailor nutes to stage of growth.

Far as Mg goes...I totally understand why you need to supplement...but do you really need the Ca and Fe and N that's in CalMag or do you just need the Mg? I prefer using Epsom salts which adds the Mg and some sulfur. The extra stuff in the CalMag may play in to what's happening with your plants...not too sure yet.
Hang in there...
ET

 

[stella]

Evil
yes, kinda
there's the veg chamber, and the flower chamber, both with their own res
what are the affects of over fert with cal/mg?

 

[EvilTwin]

Stella,
Since there are multiple elements in calmag, you have to look at each individually.

For example with Calcium, like when you were using tap water...the plants definitely didn't need the extra Ca and a Ca excess could result.

The N that's included...plants nearing the end don't want or need any N. That can slow down bud development.

Now just a little aside. I've been growing since the early 70s. SOG has always been a bunch of plants of the same age and size. You seem to have mistaken the perpetual harvest idea with sog or something...

What I think is going on is the plants are not allowed to get age specific nutrients in your system. At least as I understand what you're doing.
ET

 

[banscheee]

I agree, regardless of whether or not you keep the res in perfect condition, with plants of all different ages you are going to run into problems at one end or the other. Is it not any different to have one big harvest from several little harvest??? I mean, in my opinion you would be better off to have them at the same age and be able to tailor the reservoir to the needs of the plants. I don't disagree with the use of calmag, it is a great additive, but i disagree with having to add it to every feeding. Seems to me like there's some bigger underlying problem there.

 

[stella]

thanks all, i'll try to fluctuate my ph- i NEVER had this problem when doing ebb and flow- the DWC is a totally different animal. Some of my plants do very well -i have a bb bluecheese that yields me about 1z, but the rest of the strains are feeling it..
does anyone else grow with the perpetual harvest system?.
Hey Hydro, with regard to your recommendation, what i am currently doing is
a res change every week or so- following the lucas formula and adjusting the ph to my 6.0 ish...if my res is 8 gal, i've been adding plain ro water to keep the nute level to 1300ppm, (i have been adding about 1.5t calmag/gal with every fillup) until i've done that 8 times (8 gal), then change the res. I've also been keeping the ph between 6-6.1
If i understand you correctly, when i change the res, keep the ph about 5.2, DONT add cal mag, and watch as the ph slowly rises. BUT with a res change once every 10 days or so, how can i let the ph swing up in 20 days if im changing the res every 10?

 

[Hydro-Soil]

I've also been keeping the ph between 6-6.1
If i understand you correctly, when i change the res, keep the ph about 5.2, DONT add cal mag, and watch as the ph slowly rises. BUT with a res change once every 10 days or so, how can i let the ph swing up in 20 days if im changing the res every 10?

Easy.... stop changing your res. Keep your res topped off to the same level with RO and add nutes when the ppm drops. You already have a way to check pH and EC/ppm, why go the simple route? It's more work, does a less efficient job and wastes nutes. If you only had a way to check pH, I would say get a bigger res so it takes longer before changeout. With an EC/ppm meter, dropping the changeouts will be a breeze.

Stay Safe!


Edit: If you stick with the changeout.... mix your new batch at the same pH as the old one you just dumped.... the pH swing should continue to climb.

 

[EvilTwin]

Stella,
The deal with a ph swing vs a fixed number...well first it's much easier. When you correct, go to the lowest number of whatever range you choose. 5.2 was it? And then conduct everything normally except don't adjust ph until it reaches the top number. Then drop it all the way down to the low number again. Hard to know how long that will take with your system. With my res...I can go 3 or 4 days. If your nutes are buffered better...then it will be a longer swing. It gives the roots an opportunity to be exposed to each nutrient at it's optimal ph so you'll get better overall nute absorption.

Do an advanced search looking for thread titles only and you'll see over twenty threads on perpetual harvest. I think you'll find that most people use three or 4 separate systems and stagger the harvest accordingly.
Good luck,
ET

 

[stella]

hydro
been following your advise BUT ph is dropping not increasing..
roots showing new growth, buds filling out nicely now. I've been at 1250 ish ppm, adding pure ro water when needed. NO CAL/MAG added since my changeout last week. I have noticed some of the fan leaves showing signs of deff, but i've raised my ph to about 5.8 and will wait it out. it had been around 5.6-5.7

 

[Hydro-Soil]

hydro
been following your advise BUT ph is dropping not increasing..
roots showing new growth, buds filling out nicely now. I've been at 1250 ish ppm, adding pure ro water when needed. NO CAL/MAG added since my changeout last week. I have noticed some of the fan leaves showing signs of deff, but i've raised my ph to about 5.8 and will wait it out. it had been around 5.6-5.7

Sorry to have been gone so long... New baby in the house doesn't wait


pH dropping, when everything else is the same as it's been, is usually a sign of root issues. Hope things have stabilized since? Edit: Just re-read that you were having 70F res temps... if you haven't brought this down, it's most likely the cause of the root issues and dropping pH.

The pH swing works best when it's introduced a the beginning of flower. The plant has the first 20-30 days of ranging through the pH swing and absorbing elements. This is also the time when the plant is very demanding due to bud-set happening.

My main concern here is that you're unable to flush your plants. There's a significant difference in the quality of your end product when you can flush for 2 weeks, regardless of medium. (Dirt would go a month, in some situations) Ingesting/smoking unflushed product like you're growing there is not healthy.

Would you happen to have any way of setting up a 'Flush' tub in your flower chamber? Something you could keep fresh water in and move your plants to for their last 2 weeks before chop? You'll be VERY happy if you can do that.

Stay Safe!

 

[Anima]

What is the CFM rating on the fan that you are using? I run an aircooled 400w (cooled by a 6 inch vortex 449CFM) I can get the bulb 4-6 inches to plant tops without problems.

As said before:70 deg F is too hot for a DWC res.