PPM issue

Thread starter #1
Hey everyone, I'm running a single plant in a 3.5 gal bucket with 450w viparspectra led light. Nothing is really wrong with my plant except that it's starting week 4 of flower, and the the ppms are down in the 600's.. it's a sativa plant, and it seems to be doing great it's about 5.5ft tall with the bucket and I keep the ph right around 5.9-6.1. I use botanicare I use bloom and hydro guard I have calmag+ but don't use it because it doesn't have deficiencies. But like I said I had the ppms at 631 yesterday when I left, today it was 675 I diluted as much as I could but I watered yesterday and wasn't much room left in the res. Ph dropped to 5.8 brought it to 6.1 my ppms should be over 1000 at this point should they not? It's also not drinking tons of water. Maybe a gallon every 3-4 days. Roots look white. Anyone got a clue?
 
I had mine off the charts. Like 2000+ppm. I think better would have been 800-1100 would be more appropriate. Look at the feed charts. Most clones and seedlings I keep around 250ppm and go from there after roots are established in the solo cups.
I see no nutrient burn in the tips of your leaves but would recommend training your plant next time. By leaving the last node and leaf on your developing branches..it will strengthen and lengthen those branches and end up with 6-8 colas all absorbing same amount of light.
 
Thread starter #5
Yeah I meant to cut a lot more off waited too long tho. By training do you mean using trellis netting? And you mean cut all the suckers off and only leave the main colas on the branches at the end right?
 

TorturedSoul

420 Member of the Month October 2010
Hey everyone, I'm running a single plant in a 3.5 gal bucket with 450w viparspectra led light. Nothing is really wrong with my plant except that it's starting week 4 of flower, and the the ppms are down in the 600's.. it's a sativa plant, and it seems to be doing great it's about 5.5ft tall with the bucket and I keep the ph right around 5.9-6.1. I use botanicare I use bloom and hydro guard I have calmag+ but don't use it because it doesn't have deficiencies. But like I said I had the ppms at 631 yesterday when I left, today it was 675 I diluted as much as I could but I watered yesterday and wasn't much room left in the res. Ph dropped to 5.8 brought it to 6.1 my ppms should be over 1000 at this point should they not? It's also not drinking tons of water. Maybe a gallon every 3-4 days. Roots look white. Anyone got a clue?
Well, that LED panel is only actually consuming, what... about 200 watts? I'm guessing your tent is a 3'x3' or 4'x4' - So that's either ~22.2 or 12.5 watts per square foot (pretty low, in either case). Sure, a lot of that is falling on the plant because it's directly under the panel - but a lot of its illumination isn't falling on the plant. And sativas are light-loving plants (more so than indicas), being (mainly) equatorial/tropical ones.

Add to that the fact that many sativas are known to be light feeders, and it's not surprising that yours appears to be healthy with a more moderate nutrient concentration. You can always try ramping up your nutrients slightly - but watch for signs of nutrient burning (the tips of the leaves are often an indicator of this).

is it normal, or ok for ppms to be at 600ish this late in flower?
I wouldn't consider the start of the fourth week of flower to be late in flower when growing a sativa, lol. I've routinely seen sativa-dominant hybrids go 12 to 14 weeks, and pure(ish) sativas 16 up to 20+ weeks in flower. Has yours even finished the stretch (first 40% of flower period) yet?
 
Thread starter #7
So I had a 32x32x63 tent with that light, and the plant got too tall, so I got a bigger tent 57x57x95 with the intention of getting two 900w leds from same company because I'm growing 6 plants on an ebb and flow system next time. But don't have the lights yet or else I would put one of them in there right now. How am I suppose to tell you if it's done with 40% of flower if you just told me it could range from 12 to 20 weeks? I know my plant isn't almost done I just meant this late having 600ppms being too much it's not taking it. No matter what I do right now it will only drink water and the ppms keep going up
 
Sounds like you aren't mixing or re-adding solution quite right. The PPM's will be what you set and there isn't a hard and fast rule of what it should be. It will vary depending on what nutes you use, additives and technique - as well as source water quality.

After you mix a new batch, you need to watch it over a few days to figure out if it has not enough, enough, or too much nutes. If it's rising, then it probably means that it needs less nutes and needs to be diluted. You can remove some of the nutes if you need to add pH'd water so that the level doesn't go too high. You should end up with a ppm LOWER than it was before or it will just keep oil rising.

If it drops then it needs a higher concentration of nutes and you need to bump it up higher than it was.

When you get it right, it will stay steady as the water solution drops.

All that said - there's another cause of ppm's rising - heat/evaporation. In the warmer months, if it's in the 80's in your tent, a lot of water can be lost just due to evaporation from the rez. All that air that's being bubbled into the rez comes out through the hydroton and takes some of the water with it. IF this is the cause, then you dilute it back to where it was.

Your plant looks very stretchy from most of the plant being too far from the light. The very top is ok, but the PAR drops off steeply after 2' on LED's. Those lower branches are going to have a tough time getting enough light. A SCROG net can help you keep a nice flat canopy for even coverage.
 

TorturedSoul

420 Member of the Month October 2010
How am I suppose to tell you if it's done with 40% of flower if you just told me it could range from 12 to 20 weeks?
Most plants, when the light type/intensity is constant (during flowering), will stretch for the first 40% of flowering. So... Has it stopped stretching yet (or at least significantly slowed down, if the light situation causes/caused it to keep reaching for light)?

I know my plant isn't almost done I just meant this late having 600ppms being too much it's not taking it. No matter what I do right now it will only drink water and the ppms keep going up
Some landrace sativas are notoriously light feeders. Therefore, depending on what genetics are in the strain, it might not require heavy nutrient levels.

Other than that, you can try giving it more light to see if the reason it isn't consuming nutrients at a high rate is simply because it isn't receiving enough light-energy to need them.

And if the stretch has ended, you can ease off on the percentage of nitrogen in the nutrients.
 

TorturedSoul

420 Member of the Month October 2010
The problem is that the top of the plant is getting good light but by the middle of the plant it's not enough. The PAR drops off that fast.
From the looks of the internodal spacing and the general availability of space in that grow area, I'd say that plant would have been an excellent candidate for a scrog grow. That would have leveled the plant out into (more or less) a flat plane, which would have allowed the grower to (lower the light and) get the best use of the light - for every bud, instead of just the one(s) currently on the top of the plant. Additionally, depending on factors such as whether or not the grower minded a longer vegetative period, adequate root zone / nutrients / et cetera, a scrog would have been likely to produce a much more "full" grow space.

Seems like the higher the percentage of sativa genetics a plant exhibits, the better it works in a scrog.
 

Rifleman

Plant of the Month - November 2015 Member of the M
Hi. Can i know the source of this articule?
Thx:cheer:
Don't know the origin, but here are the notes mentioned:


*The ideal scenario you are looking to achieve is where the EC is either dropping slightly or remaining static, with a static or slightly rising ph and a dropping water level. If you get this situation, keep doing exactly what you are doing because your plant is feeding and drinking.


Note 1.
When pumping air into a nutrient solution in order to add Dissolved Oxygen, not only oxygen is present, CO2 is also pumped in. If you live near a busy road, this may be higher than normal, so you may get a dropping ph quite often. I have noticed most of the growers who suffer from a falling ph in DWC tend to live in large cities. This may not be a link but it could be.
When CO2 is added to water, it makes it more acidic. This is the precise process which causes acid rain, pollution from power stations etc pouring CO2 into the air, this mixes with the water vapour in clouds causing acid rain.

Note 2.
Most people assume that with a rising EC, it is the plants way of saying, I dont want more food, here, have some back.
What is actually happening is this.
Plants roots take in water/nutrients through a process called Osmosis. Effectively, if you think in terms of the roots having their own internal EC.
The osmosis process will always try to balance out the EC's, taking from the higher side of the barrier and giving to the lower part.
So if the EC of the nutrient solution is higher than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.
If however, the EC of the solution is higher than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution.
A res change or increase in EC should resolve depending on the other factors such as ph and water levels.

Note 3.
Nutrients flow around a well hydrated plant much more effectively and faster than one which isnt as well hydrated.
How can growers use this?
By feeding at lower levels, the plant needs to take on more water in order to get the nutrition it requires.
So by feeding at moderate levels, this forces the plant to drink more.
By drinking more, it is better hydrated, because it is better hydrated, it needs more food, making it eat more.
So feed at moderate levels rather than overly aggressive levels.
The method of pushing the EC until you see signs of nute burn is damaging to the plants and although many growers use this method, I am not a fan though your plants are not mine!