Does it matter that the roots are literally sitting in water? I read that nutrient strength, only in totality causes dehydration at a certain point, and that there actually is no such thing as individual nutrient toxicity except for the most extreme cases. Osmosis is only concerned with how much of each individual element (nitrogen, phosphorus, potassium, etc.) is present on each side of the root membrane. For example, if there is a maximum amount of phosphorus behind the root membrane, no more phosphorus from the other side will get in, if there is a maximum amount of nitrogen, no more nitrogen will get in... and so on and so forth. These are not my ideas, they are the ideas of Jorge Cervantes in his book, "Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible."

Right now, my buds are ripening in the eighth week of flowering (my strain is Aurora Indica, which has a slightly shorter flowering period than most other indicas), and I am experimenting with a solution of 1450 ppm, which is a little high, even for an indica (indicas in general use a much stronger solution than sativas). The roots are suspended in water almost directly and completely with only a thin layer of clay between a 4x4 block of rockwool and the solution.

Are you running a DWC type grow. Air stones and all that?

That's way higher ppm than I use in late flowering in my DWCs tho I've been that high in late veg and early flowering.

Are you seeing any drying up of fan leaves?

I have at higher ppm during late flower so I let it drop to about 500 before the 8th week.

Not sure about when you might see dehydration from nute strength. Never had it happen.

Idicas in week 8 of flower? Why arn't you flushing? I wouldve started my flush a week or two ago. Just sayin

I guess you could call it a DWC... there are two pics attached to my other thread, "show off your STATE OF THE ART hydro setups." The clay medium is wider than usual though, to promote spread-out rooting.

All the leaves are green and healthy... more resin than I've ever seen on them. For all intents and purposes, they are Afghan plants. They have been adapted to indoor growing by a Northern Lights cross.

Do you grow sativas, indicas, or hybrids? Indicas require very high ppm. The more indica there is in a cross, the higher ppm it requires. Since the start of the grow, I haven't had one leaf show signs of deficiency. I am using an MH Sunmaster Warm Deluxe instead of an HPS... that might be part of the reason I have almost zero nitrogen right now in my solution, and my leaves are still green and healthy. Also, I have added lots of Botanicare Sweet Grape to handle the "macro" processes. There is still a lot of blue light coming from the Warm Deluxe, and I think that is the reason the buds are as dense as cement!

Eight weeks is short man. I've studied every single feminized indica (as well as the sativas and hybrids) on the Nirvana website and almost every indica or predominant indica is 8-10, or 9-11 weeks. Aurora indica has the shortest flowering period on there (7-9 weeks) and is known for it everywhere else, including many other websites.

Google the name of any strain and type "pics" after it, and you will get hundreds of straightforward profiles and specs.

Wow you read the profile on a bunch of strains, you much be an expert grower now. . .

You do understand those are estimates right? and most indica dom strains don't go much longer than 9 weeks. being at week eight you might want to let those plants go to week 10 so you can flush everything out. Also that late in flower you don't want your plant to be green you want it to start devouring itself (turning yellow)

The original question is actually a pretty good one.

All of last lear my favorite strain was White Ruski from m seeds nl, usually my target tds was 850ppm (@.7EC conversion), but as I always see, annoyingly, all of the "sisters" aren't the same. One of them I was able to hit 1400 or so without problems. I selected the best one and just dialed that in over a few grows. Then i quit growing all together for a while to rebuild my whole setup. On my current grow, I grew a few new WR plants, tried to hit that number, and the plants were not looking good.

So I dropped it back down to about 800, and interestingly enough, the buds all took up way more water, to the point where they all fell down, the stems could not hold them up. They also started to look a lot better.

I really felt stupid after doing this, realizing I should have never gone that high with the tds to start. My growing style relies on the buds sagging and falling down to stay out of the lights. I cut this tub down yesterday and threw almost all of it in the trash. 9 weeks to fill a big bucket with garbage. Oh well. I didn't get any good sisters (phenotypes?) like last year out of these 10 seeds, guess I'll have to order more. 1 looks pretty good, I did clone it, but still.

But the real answer is all plants, growing systems, environments are different, as I always say, you have to experiment.

The other plants I am growing I am at anywhere from 800 to 1400ppm, and they don't seem to really care much either way. In general though, the lowest tds you can go without deficiencies, light leaves, the better. A higher tds than necessary slows the growth rates, makes the buds lower quality, etc, and adds time to your flush too.

In aero I was only hitting 360ppm (!) with C99 I got from a guy on here. The plants would grow up, the buds would form, fill in a little, all fall over and get crystally exactly like I wanted.

Wow...and I am seeing completely different results? I have been playing around with strengths of nutes to see if I can increase quantity or to see what it does to flavor. This is what I have found out over the course of a year.

I orignally ran a max of 1400ppm in the 5th and 6th week then over the last 10-14 days I tapered it down to just water. I am averaging 13-14 zips a plant. Starting my flower at 1400ppm and finishing around 1850ppm has suprised me a little! I am now averaging between 14-16 zips.

What came with the increase?...TASTE! With my standard flushing there remained a gritty flavor at the back of the throat. I have increased my flushing time by almost a week and the taste is better but still there.

To see the girls side by side the only difference was a slightly darker green and the girl on high nutes kept her green all the way to the end. The formation of buds looked the same but density was definetly different.

I am convinced that finding the max ppm per strain will benifet the overall quantity and finding the proper flushing technique
should eliviate the taste?

I hope!

yup 8 to 10 weeks. You said you are in week 8, start flushing or enjoy the chemical taste that will be the end result you will have, why go to all this work and then fuck up the ending?

I would have to agree, higher ppms during flower can indeed create a higher yield but if a minimum 2 week flush is not done the taste suffers drastically. I have even gotten to where I am often flushing for 3 weeks. Doing this has caused me to lose some yield but the quality difference is phenomenal. I can now put my hydro up against any soil or even (I know I am inviting an argument here) organics. I recently sat with some folks that smoke nothing but organic and broke a bowl of my bud out and they did not know it wasnt organic. They couldnt tell. hmmm.