Nebula starting to yellow at day 33 flowering.

[XtaS]

Hello fellow tokers and excuse me my not fluent English, hope you get the point and we're all happy

Here I am, a newbie hydro grower and starting to panic because my precious lady Paradise Seeds feminized Nebula is starting to yellow its sun leaves at day 33 flowering. This is just my second hydro grow and I'm using one waterfarm. Last grow went hmm, pretty okay but now I have high hopes with this strain, never smoked it though but heard a lot of good things about her.

I found this form which I should obviously use so here we go:

HYDROPONICS:

What STRAIN are you growing?
Paradise Seeds Nebula, feminized seeds.
What was the establishing technique? (Were the seed or clone?)
Seed
What is the age of your plants?
Total 76 days which been flowering 33days today.
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in?
Flower
What Technique are you using?
Nothing particular, a little LST and topped the plant on sixth node.
What substrate/medium are you using?(Hydroton, RockWool etc.)
I planted on rockwool cube which is places among clay pepples in waterfarms top res.
What Nutrient's are you using?
GHE Flora Bloom, Micro, (very very little gro because I'm trying to run Lucas formula.) Growth technology Liquid Silicon and GHE Ph-Down.
What is the TDS/EC/PPM you are using?
I've tried to keep it at 1,1 - 1,5 EC
What is the pH of the "Tank"?
Its been 5-6 usually.
Are you sure your calibration is correct on your equiptment?
Pretty sure.
When was your last watering?
Well, I usually add 3 litres of water every 2 days to res and according to EC and PH, I give some nutes/ph-up too. I've tried to give her Liquid Silicon 0,5ml / 1 litre of water to prevent any root problems and yet, I've succeeded to not have one.
When was your last feeding change? (ie. grow-bloom-micro-additional)
About 4weeks ago when I changed all waters and threw her to blooming closet.
What size bulb are you using?
400W HPS with cooltube.
What is the distance to the canopy?
about 18-25 centimeters.
What is your RH Factor?
Lights on and extra fan rolling humidity is 20-25% and when lights off 40-55%. When lights off I only have Systemair 225 m³/h fan and activ carbon filter on. (they are on when lights on of course too)
What is the Day/Night Temp? (Include flucutaion range)
Night temperature 23-24 celcius degrees and day temperature is about 26-39C.
What is the current Air Flow? (cfm etc.)
225 m³/h.
Is the fan blowing directly at plants?
Yes at daytime. not when lights off, no room for fan and closed closet.
Is your water HARD or SOFT?
Soft, EC is 0,14.
Has plant been recently pruned, cloned off of or pinched
No, the plant is untouched except few 4-5 yellow and dried leaves I took off because they haven't dropped.
Have any pest chemicals been used? If so, What and When?
No.
Are plant's infected with pest's
No.


Well, the problem is the biggest leaves are turning yellow which I'm a bit worried because the plant has been flowering only 4,5 weeks now and I guess its not supposed to start dropping the leaves yet?
The biggest concern is I'm not all that experienced with growing about ten or so soil grows and now second with waterfarm so I call myself a beginner. I'm not all sure am I just panicing without any real reason.

Last time I changed the waters were when I changed her from veg closet to blooming closet. By then I added 10ml GHE Flora Micro, 20ml GHE Flora Bloom, 10ml Liquid Silicon(5% potassium silicate) for 10(ten) litres of water and fixed the ph to correct I've just tried to keep my EC on that value.

When I first noticed some yellowing about a week ago I gave her a bit more food but didn't saw any difference. Then I gave her some gro (which I don't use usually, just to fix some deficiences if they occur) and micro more there were some improvements but eventually I'm currently at a point I don't know what to do.

But I would like to hear Your experiences about Nebula and would be even better if the setup is even a bit like mine but every single tip and saying hello is appreciated.

Here are a few photos about the situation:

Heres already some trichomes!

If any questions, please feel free to ask.

 

[Row]

Hey XtaS,

Plants look awesome dude,

Looks alot like the problem i am having, though more like a textbook N deficiency. link to the post is here,

http://www.icmag.com/ic/showthread.php?t=119448

It seems that i was just having a N deficiency and isnt to much to worry about at that stage of flowering,

I personally wanted to see them stay greener for a week or 2 more but Mynamestitch who i really respect in the whole diagnosing nute problems said she didnt think it was anything to worry about and they were loosing the N at the right time and everything was fine.

I definitely think they just look like there a little N deff and its nothing to worry about, they look dam nice to me.

Row

 

[Weedninja]

2 things are jumping out at me. #1 is that you need to be changing your reservoir more than you are. You should change it every 1 or 2 weeks. Don't just top it off when water evaporates.

#2 is that a pH range of 5-6 is a big change. Did you know that pH 5 is 10 times as acidic as pH 6?

 

[10k]

The other thing that jumps off the page for me is the nute mixing strategy.
Running a very weak lucas mix, then adding the potassium silicate which no doubt spikes the hell out of the mix, requiring the addition of pH down to counteract the spike. That plus a somewhat faulty add back strategy will surely give have you running a badly "damaged" res mix.

They look hungry, and this may just be a matter of running the damaged and weak nute solution as far as the flora portions...
A good portion of that ec is the silicone and the acid needed to fix that silicone spike imho, and not the gh flora series components.

 

[XtaS]

Thanks for stopping by Row, Weedninja and 10k.

Weedninja, yes I was aware of about the ph 6 being 10 times more acidic than 5 and I've tried to keep it at same point as much as I can but i takes approx 1 week and then I need to set it again from six to five. Its not everydayjob but about once a week it gets from five to six. I don't have fancy digital ph meter so the numbers ain't that accurate but they give me ne needed information.

I've been thinking about changing waters in the res every 2 weeks but I've read from around that it has to be done even every week if you don't have a EC-meter but I do and I can see my nutes strenght in res so I figured out I can do vegging with one res change and blooiming with one, and final flush but maybe I was wrong.

For 10k, what do you mean by damaged res mix and like you said I'm running weak lucas mix. Would you suggest me to feed them more, like I've said on the first post I'm still a newbie with hydro stuff so every possible hint is welcome.

 

[10k]

How are you going about the add backs or topping off the nutes in the water farm bucket ?

By that I mean, in any particular order like water first then nute concentrates then pH adjustment concentrates etc ?

And then after adjusting pH or adding that silicone additive, do you find yourself adding in even more water to bring the ec back down to the strength you're looking for ?

Do you also find that you have to readjust the pH back down again after you add the silicone additive ?

 

[XtaS]

Thanks for spelling it out for me.

I measure my res EC every day and if I see her taking more nutes than water I add some nutes as the EC is going down. Always I see I need to add something, I fill the res with water, measure EC and PH by taking a glass of water from the res and add whats needed to glass, for example 4ml micro, 8ml bloom and 2ml liquid silicon if the ph has went too down by time. If I add Liquid Silicon I add it first to glass, then nutes. I'm not adding silicon on every time I add water, just when I need to get ph up a bit. Usually once a week for few ml's. The bottle says I should use 1ml/1litre of water but I'm not going that high doses.

After I've spilled the glass to ress, I let farm run about an hour and then measure EC and PH again to see thei are now what I want them to be.
I havn't yet had a problem with too high EC, I mean I havn't needed to add more water to res to get my EC down. Its usually on full res 1,5 and after 2days not adding water EC gets to approx 1,7-1,9 and then I need to add ~3litres of water and then I measure EC and PH and correct them to wanted scale.

For question about do I find myself readjusting ph back down after silica the answer is no because I usually use it for just getting ph up. In the first post I say I use silica 0,5ml / 1litre, I put it that way because its approximitely how much I use it compared to water I add to res.

Heres situation today:

I hope this text wasn't too hard to understand, had a nice just before checking back in.

I had some of this Yumbolt 47 ( my first hydro grow)

 

[10k]

Thanks for spelling it out for me.

I measure my res EC every day and if I see her taking more nutes than water I add some nutes as the EC is going down. Always I see I need to add something, I fill the res with water, measure EC and PH by taking a glass of water from the res and add whats needed to glass, for example 4ml micro, 8ml bloom and 2ml liquid silicon if the ph has went too down by time. If I add Liquid Silicon I add it first to glass, then nutes. I'm not adding silicon on every time I add water, just when I need to get ph up a bit. Usually once a week for few ml's. The bottle says I should use 1ml/1litre of water but I'm not going that high doses.

After I've spilled the glass to ress, I let farm run about an hour and then measure EC and PH again to see thei are now what I want them to be.
I havn't yet had a problem with too high EC, I mean I havn't needed to add more water to res to get my EC down. Its usually on full res 1,5 and after 2days not adding water EC gets to approx 1,7-1,9 and then I need to add ~3litres of water and then I measure EC and PH and correct them to wanted scale.

For question about do I find myself readjusting ph back down after silica the answer is no because I usually use it for just getting ph up. In the first post I say I use silica 0,5ml / 1litre, I put it that way because its approximitely how much I use it compared to water I add to res.

HI XtaS,
Please don't get the impression that I'm nit picking your methods. I'd just like to talk a little bit about nute mixing strategies, add backs top offs and what I mean by a "damaged" res mix.... In the near future I will be writing a paper on this topic, but for now since you asked I'll just get to some of the nitty grittty

Multi-part nute concentrates, such as your gh flora series nutes are in separate bottles for a very good reason. There is a specific mixing order for final mixing in which the micro concentrate always go in the water first, followed by the grow and/or the bloom concentrates. This is to prevent any of the elements from precipitating within the mixed solution. When and if elements precipitate, several key elements can become unavailable to the plants and some can even become toxic. This can result in things being somewhat 'out of whack' in the plants food uptake and plants can develop what looks like defs, tox's and lockouts over time from eating an imbalanced nutrient diet.

By the same token, when an already mixed nute solution has additional nute concentrates added to it the same precipitation can happen. The concentrates should always be added to as large an amount of water as possible initially, and when doing add backs to an existing mix it is much better to add freshly mixed complete nute solution to the reservoir, rather then adding raw nute concentrates to the existing mix. That raw concentrate added into the existing mix can cause some elements precipitate at the point of contact with the solution just like the micros would if you had added them into your initial mix last instead of first.

Precipitation also can occur when the pH gets too high within the mixed solution. It also happens to a lesser extent when adding pH adjusting concentrates to the nute solution. So it's always best to add the acid or base to the solution in a 'pre-diluted' form. IE: acid diluted in water, then added into the res while vigorously stirring the solution as its poured in. Same for base chems like potassium hydroxide pH up or potassium silicate silicone treatments (a great pH up btw)

That thing you did XtaS, when you took out a glass of existing solution, then added 4ml micro, 8ml bloom and 2ml potassium silicate. IS a prime example of what NOT to do. For one thing, you added a relatively big dose (relative to the glass) to a small amount of water. Secondly, the potassium silicate would have driven the solution pH way up in that glass and subsequently would have been a shocky concentrated pH hit into the existing mix. All of which can cause some precipitation to take place in your reservoir solution.

All of these above practices add up to what I call a "damaged" nute mix.

There's a couple ways to skin a cat as they say, regarding reservoir maintenance.
Trying to continuously hold one specific TDS or EC is futile and not great for the plants imnsho.
Plants will uptake what they desire from the nute solution over time, some elements faster and sooner than others, as a result they can uptake too much of certain things and not enough of other things if not governed somewhat by what is available in their 'food bowl'. As a result of that, they can leave the food bowl somewhat imbalanced too, ie: missing large amounts of some key elements and having too much of other elements, sometimes the build up can leave some of the leftovers at toxic high levels.

Because of this, in small hydro systems it is easier and better for the plants to practice a res topping procedure as follows... Daily topping off of the res solution.
Not trying to continuously hold a tight tds number, but instead allowing it to swing up and down somewhat over time and changing it out with a completely fresh mix every ten days to two weeks. Two weeks being my preference.

This can be best accomplished by adding straight water one day and then adding a premixed nute solution the following day. Alternating water or nute solution every other day. Your topping nutes need to be roughly half of the strength you use for the initial res mix. If you have your plants dialed into a desired TDS for example 1000ppm, then you would add back a premixed solution which is 500ppm every other day, alternating days with just plain water. This method WILL hold your target ppm fairly close to the target range IME. Of course, adjust the pH each time you top the res (your hydrofarm) using only water pre-diluted pH chems...never concentrated so damage can not occur.

By having a separate premixed drum of nutes for the add back, you will not be taking any chance of having a damaged nute solution in your hydrofarm(s). Two ways to deal with the holding drum One way is to mix the drum to the target strength and keep it that, using it for initial res fills and half'ing the premixed solution with water each time you measure out your nute top offs, or the other way where the grower mixes a larger than needed batch of nutes for the initial res fill and then halfs the strength of the remainder with water for top off usage. You can use a large plastic waste can or plastic garbage can for your mixing drum(s), works great.

pH range of 5.1 to 5.9 (with 5.2 being optimal)
Chem nute solutions will always go up pH wise. You want to allow the pH to swing through a range rather than trying to constantly adjust it to a specific number. This allows a varying range of elements to be available for the plants instead of holding them to any one specific degree or amount of each element all the time.
It is impossible to hold a tight number anyway, so let it swing through the range.

About mixing multi-part nutes like gh flora series...

Initially you stated this...

Last time I changed the waters were when I changed her from veg closet to blooming closet. By then I added 10ml GHE Flora Micro, 20ml GHE Flora Bloom, 10ml Liquid Silicon(5% potassium silicate) for 10(ten) litres of water and fixed the ph to correct I've just tried to keep my EC on that value.

Considering your ongoing res mix and how you went about it, you are probably experiencing lockouts from a precipitation having happened in the reservoir mix. You're essentially running a very weak lucas ratio, then spiking the pH with the potassium silicate, then running the pH back down with phosphoric acid.
A large amount of the EC you are measuring is the additives and not the lucas formula you're mixing, which is why in my opinion your plants look like they're hungry.
They still look good, but they do look hungry

I'd go ahead and dump that existing somewhat "damaged" mix and replace it the following way...

In a separate mixing tub. Go with a small plastic garbage can so you have plenty of room to make your final mix in it without adding things in to hit your target ec. I'd get a can big enough to hold at least ten gallons or more of water. Rubbermaid or similar new plastic garbage cans work great for this.

To begin, I would mix a five gallon batch of full strength 0-8-16 (ml per gal) ratio lucas mix...First I would put four gallons of water in the mixing res and then add 40ml of flora-micro mixing it thoroughly into the water. Then in a separate gallon of water I would add 80ml of flora-bloom mixing it well and then gradually mixing that gallon into the other four gallons.

The above will now give you a full strength five gallon batch which you will then add more straight water into until you reach your reservoirs target ec.
Once you've mixed this dilution it is ready for you to adjust pH if need be.

The pH adjuster 'pre-mixes"...
Premix yourself a diluted bottle of potassium silicate to use for a pH up / silicone treatment.
Doing this will help keep you from spiking the hell out of the pH in the res when you're trying to silicone treat or pH up the res. A lot of growers screw up the reservoir adding silicone as it IS very strong and its way too easy to spike the pH out of range in the process, which in turn would cause you to have to adjust it back down again with pH down (phosphoric acid), a practice many hydro guys end up doing of which can mess up a res and horribly damage the final mix in the process

So lets mix a diluted bottle of the potassium silicate. (Great pH down and silicone supplement)
In a plastic 16 or 20 ounce soda bottle, place about 16 or so ounces of water and then add about 20ml or so of your liquid silicone additive.
(potassium silicate aka ProTekt)

Do the same thing with your Phosphoric acid pH down. Mix a small soda bottle of water with about an ounce or two (This depends on how strong your pH down concentrate is to begin with) of your pH down chemical into this bottle so you have weak dilute acid solution.

So now you if your target range ec res needs adjustment to arrive at a desired 5.1 new batch start pH, add the dilluted adjusters to your nute mixing drum gradually while stirring the drum contents so that its moving at the point of contact where the chems are being poured in and you wont be causing any precipitation in the solution.

Holy crap I've gone and written another book

hth,
10k

 

[XtaS]

10k Thank YOU very much for your good helpfull text. hydrogrowers handbook for mixing nutes.

Well I will change my res tonight and do it correctly this time. I really suggest everyone to read the text above what 10k said about the mixing nutes and everything if your not familiar with it already. Thanks for your support.