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Ace Malawi and Cycloptics Greenbeams: caught in the Under Current!

rykus

Member
Not going to be a rude about it, but lowering the oxygen also lowers potential growth which would make the lower nutrients seem temporarily better, but beware in Water culture oxygen is key....

I know we're all just anyone with a keypad but I think your limiting yourself and I know your limiting your plants by not feeding. That's like saying a champion athlete will be more efficient on less food at higher altitude because ?

Why is it that they magically made plants require less food by increasing oxygen to the roots?

Doesn't make sense IMO, but even if you don't want to up food, lowering o2 will lead to root issues....
 

timmur

Well-known member
Veteran
Not going to be a rude about it, but lowering the oxygen also lowers potential growth which would make the lower nutrients seem temporarily better, but beware in Water culture oxygen is key....

I know we're all just anyone with a keypad but I think your limiting yourself and I know your limiting your plants by not feeding. That's like saying a champion athlete will be more efficient on less food at higher altitude because ?

Why is it that they magically made plants require less food by increasing oxygen to the roots?

Doesn't make sense IMO, but even if you don't want to up food, lowering o2 will lead to root issues....

Hey rykus I hear what you're saying, but guys who are absolutely killing it in the UC are doing something like this. I'm not clear on the science other than to say that nutrient efficiency goes way up when saturated O2 levels are achieved.

Just to be clear, I ditched the O2 Grow for now as I believe it was over oxygenating the epicenter while the modules were well below saturation (try 50%). My testing now indicates a nearly steady 90%-100%% oxygenation in the epicenter and 85% or better in the modules. As I mentioned previously, there was mineral precipitation in some of the modules and a lot of it in the epicenter. I believe this was due to very high (super saturated) DO levels. Too much O2 can be detrimental.

PPM : 200
PH SWING 5.8 TO 6.2
Humidity: 50 %
Temp: 78 to 80
CO2 : 1000 PPM

3 Weeks in Veg

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Also, see the pics below of my plants after dropping the PPM to 100 (.20 EC). They instantly perked up. I'm not saying they are doing great, far from it. They still look like they have a mag deficiency, but they aren't wilted like they were and the tips aren't burning like they were.

 
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timmur

Well-known member
Veteran
Nutrient Efficiency and Dissolved O2

Nutrient Efficiency and Dissolved O2

This is a copy paste from a paper I found on the interwebs.

Why Is Dissolved Oxygen Important To Plants?
Everyone knows that carbon dioxide is required by plants for photosynthesis – that green plants convert light energy to chemical energy (sugars). Plants also require oxygen to survive. It is an essential element. The root system requires oxygen for aerobic respiration, an essential process that releases the energy required for healthy root growth and a healthy plant.
Research shows that higher dissolved oxygen levels in the root zone of most crops results in a higher root mass. A plant with more root mass grows healthier and faster. A plant’s roots are where it gets the majority of its inputs for growth, including water and nutrients. Healthy roots with a good supply of oxygen have better respiration and are able to selectively absorb more ions in solution, such as the vital mineral salts nitrogen, phosphorus and potassium. When there is less oxygen in the water than there is in the plant this reduces the permeability of roots to water therefore reducing (even reversing) the absorption of nutrients.

I've attached the rest if you care to read it. It should be clear why systems like the UC can use such low levels of nutrients relative to other hydro methods and have such amazing results.
 

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frostqueen

Active member
my 5 cents
For the strong growth of the root system recommend adding P, your plants shout about the lack of P
Phosphorus is very important in a period of growth of the root. I recommend calculate the solution.
400-450 ppm works fine to veg. and pre-bloom... 70-80 of them must be phosphorus.
At such levels of ppm you can raise a lot of types of genetics.
I borrowed these figures from a friend breeder , he passed through a lot of different genetics in rdwc systems (diy and UC)
these figures works for Malawi also, only a phosphorus must be managed , take it easy :tiphat:

I agree with this. Adding a small amount of straight phosphorous right now could really get those roots to explode, as well as boost overall energy in the plant. This would be in addition to their current CC nutrients, not instead of.

I'll again plug RAW's phosphorous for this. I don't work for them, but that nutrient line has really stepped up my game quite a bit so I feel compelled to mention them again. The level of control you get from using individually packaged nutrient components is making me much more aware of the importance of giving plants exactly what they need exactly when they need it most. I am reviewing them in another thread.

I agree with you that following Current Culture's recommended nute strength makes sense until you get a feel for it. The wild card here is that you are growing an untested (by you) tropical sativa strain with these nutes. You are doing just fine at it, too; there's going to be some variability with it. These plants are actually looking a lot better now; you are in the ballpark.

You will definitely get a much better idea of how much CC to use when you run a previously-grown strain.

I just saw that you are staying within 5.8-6.2 ph... there is so much that happens below 5.8 in hydroponics, down to about 5.5... nothing above 6 is necessary IMO... just sayin'. JMO.

Keep up the great work. So jelly of your grow scene. Very inspiring.
 

timmur

Well-known member
Veteran
Nice bushes, are you planning to top them or let them grow untouched?

I planned on mainlining, but now I'm not sure. I really expected to be further along than this by now. I will top, but I may not mainline. I've been tempted to takes some clones and start over, but I can't bring myself to do that.
 

timmur

Well-known member
Veteran
So just another update. I checked the ec yesterday and it was at .28 or about 165 PPM on the 500 scale. When I got home from work the ec was at .18! They are finally eating and growing like they should've for weeks! :dance:

The tallest plant, which seems very stretchy and lanky, grew about 2 inches in one day. The others are much shorter and more bush like with a bit wider leaves. To my eye, there appaers to be two main phenotypes: the lanky stretchy one with the skinnier leaves and the shorter squatter one with somewhat wider leaves. Question for dubi or anyone else that knows, how many different phenos of malawi are there and how many do you see in the pics? I know the pics haven't been great, but I can bust out the good camera if necessary.

Stretchy Girl
 

Bmac1

Well-known member
Veteran
You might have to fold that girl in half and hang on when you switch to flower, lol.
 

TnTLabs

Active member
if anything id take a few clones, for the next cycle.. more from the bigger ones, to even out the canopy... but yeah things looking much better... time to think bout flipping soon
 

HHULKK

Member
hey just following along for the inspiration to go gb myself. things are looking like they've bounced back for you. my guess is 2-3 phenos, 2 being very distinct, bushy and the other tall. the runts may end up being one of the 2. good job on the under current. I see your techy mad scientist approach which is very motivating. makes me wanna improve my old ways. thanks and keep on with the great show!
 

vcasqui

Active member
wow, big plants you have there. I've read a lot about DWC in the past, because I want to have my own system one day (when I live in a place that is not almost 100yrs old with no insulation [10ºC winter, 30ºC summer]).

What nutrient profile are you using? I read that you are having a little bit of trouble with Mg/Ca I think? I would recommend you to use almost 1N:1Ca.

I'm sure you already did, because you have been gathering info for almost 2 years I think you said, but you should read the Fatman's threads, you have some really nice info there.

Greetings.
 

timmur

Well-known member
Veteran
hey just following along for the inspiration to go gb myself. things are looking like they've bounced back for you. my guess is 2-3 phenos, 2 being very distinct, bushy and the other tall. the runts may end up being one of the 2. good job on the under current. I see your techy mad scientist approach which is very motivating. makes me wanna improve my old ways. thanks and keep on with the great show!

Thanks! Go for the GBs for the win. They really are a great light. :)
 

timmur

Well-known member
Veteran
wow, big plants you have there. I've read a lot about DWC in the past, because I want to have my own system one day (when I live in a place that is not almost 100yrs old with no insulation [10ºC winter, 30ºC summer]).

What nutrient profile are you using? I read that you are having a little bit of trouble with Mg/Ca I think? I would recommend you to use almost 1N:1Ca.

I'm sure you already did, because you have been gathering info for almost 2 years I think you said, but you should read the Fatman's threads, you have some really nice info there.

Greetings.

Definitely struggled with getting the nutes dialed in. I think I was locked out and the O2 Grow may have oxidized the mag and iron. Two years of reading is nice, but nothing beats some hands on experience to really figure things out! :biggrin:
 

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