New to growing! Need help with understanding nutrient levels and light distances.

[tonyh]

Hey guys! My name is Tony and I will be starting my first grow in about a week from now. I have a 70x70x160 cm grow tent with a Mars Hydro 2 400w LED light and two Lasko 6'' clip on fans for ventilation/cooling. I want to grow 2 plants in 3 gal fabric pots using coco as a medium. I have the general hydroponics floraseries nutes along with calimagic and pH adjuster. I have a few questions.

1.) From seedling to veg to flower to harvest, how far should i keep my light (400w LED) away from my plant?
2.) After germination, when the seed is planted in a small cup, should I feed her with water only? or should i feed with water + calimagic? or should i feed with water + calimagic + low strength nutes? Should I soak the coco with water (or nutrients) before planting the seed too? *Note -- I am using distilled water*
3.) When do I know when to start feeding my plant nutrients. (and how much should i feed them?)
4.) Why in some cases (like H3ADs formula) do people not use FloraGrow? They instead use ratios like 6/9 Micro/Bloom... What do these numbers mean?
5.) Should I water my plant until it is leaking from the bottom (run-off) every time?
6.) Should the recommended doses on the general hydroponics floraseries bottles be followed? or the nutrient schedule on their website?

I am pretty lost and appreciate any attempt at answering any of these questions! Thanks for the help!

[Canuck147]

Hey tonyh, from above you sound good to grow man. I'll give you my $.02 on your questions.
1. Manufacturer has those distances for you. But you would start a bit closer at first to coax the little alien out of your medium, then higher after they gain some green.
2. water only. I grow in with a soil medium and don't use coco so I'm not sure on that.
3. depends on how well they are growing. And what kind are you planning to grow? autos or photos? second week for sure give them 1/4 strength nutes and full calmag.
4. don't know what H3ADs are, sorry.
5. depends on the age. if she just popped out of the soil, just give a little bit. This part is all common sense, and is the reason most house plants die in residents households. cuz they're OVERWATERED. Pick up your fabric pot when you first put the growing medium in it. That is how it feel dry and wants to be watered. Something to remember.
6. follow the recommended doses, but start at 1/4 strength.
Sorry for all the babbling but I just smoked a joint!

[Braink]

Hello tonyh I'm on my first grow as well. I have not fed any nutes until around 2- 2 1/2 weeks at 1/4 strength. Im still unsure if I'm supposed to give a lot or just a little and the rest PH'd water. But what I do know is that for soil you ABSOLUTELY MUST PH YOUR WATER!!!!! PH PH PH and PH again to make sure the water is at the proper alkalinity for nutrient passage to the plant. I have an auto and a few photos and like I said im still trying to figure this out and when to start changing the veg to bloom etc. If I find out a little more I'll update.

[tonyh]

6. follow the recommended doses, but start at 1/4 strength.

Hey guys I appreciate the responses! I am growing white widow photo plants. When you say 1/4 strength are you referring to full strength being 1tsp (5mL) or what they recommend on the bottle? Like when you say "full calmag" does that mean 5mL?

[Canuck147]

1/4 teaspoon per gallon yup. on the calmag maybe just 3/4 teaspoon per gallon. that's what I've been doing for 5 autos that are just weeks old. even at that I see I have a little nute burn on one plant. i'm using 3 gallon soil pots.

[steve]

LED light distance 12 to 16 inches - don't use water run-off

[Weasel]

....But what I do know is that for soil you ABSOLUTELY MUST PH YOUR WATER!!!!! PH PH PH and PH again to make sure the water is at the proper alkalinity for nutrient passage to the plant....

I have to respectfully disagree here Braink on a couple points.
Soil growers generally don't have to ph anything. Soil has great buffering qualities and is the one growing medium that generally does not need constant ph monitoring. That's why we don't normally adjust ph of everything we put in our outside vegetable gardens and greenhouses.

Plain water in general shouldn't need pH adjustment. The reason for that is water, unless it's very impure, should have a very low ppm (parts per million) of added substances. The ph of a low ppm solution is very easily shifted. For example, one drop of ph down in plain water will shift its ph very drastically. It will give a very acidic reading. But because it's still low ppm, and another drop or two of ph down or ph up will easily shift it again- it's basically an empty value.
So the reverse is true - adding that low ppm plain water to your growing medium is going to have very little effect on the ph of your growing medium.
If your water is very hard, which tapwater could well be, and contains a lot of minerals then it could certainly need adjustment. But rainwater, bottled distilled water, RO, etc, never will.

When growing in hydro or soilless (coco, peat moss, perlite, etc) nutrient mixes, and basically any solution being fed to the plant other than plain water, should definitely always be ph adjusted.

Since the OP actually said he's growing in coco, not soil, he definitely does need to monitor ph.
I ph to about 5.6 for soilless and hydro. But I don't ph plain water.
It won't hurt anything if you do that, it's just not necessary.

Kind of long winded but does this make sense to you?

[Nartak]

Again have to agree,im doing a second parallel grow in my hydro tent with a soul mix growing a Choco Haze and have never Ph adjusted,she is looking great all the time and growing beautiful! I to add nutes to the water every time as the soil im using is empty from them,no cal-mag or anything else,just veg nutes from Canna...

Weasel,i have been keeping 6.0 for my drip irrigation system,i found 5.8 made the plants look better,you think i should take it lwoer than 6?

[Braink]

Hey guys. Ive been doing reading for some time on this site and a few books. I'm curious you guys say ph soil is not necessary but can you please explain why the site everyone is recommended to specifically has a suggested ph chart for, not only hydro but, soil? http://www.growweedeasy.com/ph
When i add ferts and nutes the ph level is way too low for nutrient transport. Im using tap water and sometimes filtered drinking water. All ph'd.

[Nartak]

If you are precise at feeding dosage and know your medium's buffer-ability you can easily water with 0.5 extra ph (6.5 is my tap water ph) ...I saw that my ph will come out 6.3 no matter what i give it so i know i don't have to use anything,again my soil is simple mixture,nothing with extra EC or balancing minerals in there...Just simple bagsoil...

[Bikerstonrr]

#1. Check your manufacturers website, I use the Mars Hydro Mars300 and that is where I found my info.
#2 and all nute ?'s. On GWE's main website there a ton of tutorials that will answer all of your questions plus more. Specifically for nute questions www.growweedeasy.com/nutrients. For general tutorials www.growweedeasy.com. For your ladies sakes take some time and check it out.

[Weasel]

Ok here's my take on it. I'm not a ph expert or anything just a regular grower and this is my understanding from what I've read and experienced while growing. I'm not even a soil cannabis grower- so probably you could go online or get a gardening book and get a much better written explanation than this one but wtf...

to answer the question - that ph range given is one that the plant enjoys- but we don't be necessarily need to be in charge of managing that range. Nature should do it for us.

Here is a ph uptake chart for soil. Worth spending time looking at whenever you get deficiencies.
Keep in mind that the ph scale is logarithmic. One full point on the scale is ten times as high/low as the next point. A ph of 6,6 is three times as high as a ph of 6.3. So small changes on the chart are actually very large shifts in ph.




This chart is actually super simplified and nutrient uptakes don't just end like that , they taper off gently and there's maybe a little more wiggle room than shown.



Plants growing in soil will uptake nutrients, on average, in a ph zone ranging from 6- 7. That's just the overall range in which the most nutrients are available to the plant to utilize. In reality each nutrient has a specific ph range of its own. Some of them barely fall within that range. For example Phosphorus and Calcium appear to be locked out at 6 and lower, while Zinc and (again) Phosphorus are getting locked out at anything above 7. Along with several others.

That recommended range is kind of an average middle of the road range cited to take in the most nutrients possible. In reality you need that swing between the low end of it and the high end of it. That's accomplished mostly by the minerals in the soil, such as dolomite lime in particular, which is commonly added to soil to neutralize it. Dolomite lime has a ph of about 7. There are other substances in soil which also tend to regulate ph, like compost, clay, etc. This means that whatever solution is dumped in the soil, the lime, etc, will shift it towards 7. Lime is incredibly good at doing this. It lasts for years and is a very powerful buffering agent. So, barring some extreme abuse- your soil should be able to handle nutrient mixes that haven't been ph adjusted.

In general most added nutrients are acidic. So the usual routine is that you're adding an acidic mix, and it climbs in the soil, from its reaction with the soil ingredients as well as some other processes occurring in the root zone.
So you can feed quite low (acidic) and it will work out fine because your plant will have better access to all the nutrients.
If you feed and water high however, you may be causing problems.

There are other circumstances. Not all soil mixes are perfect and you might get an acidic soil mix and have issues with it but any good well-made soil will buffer your pH.

As for plain water- it's so easily shifted by the buffering ability of the soil that it doesn't really matter what ph of it is. The ph of a low ppm solution is easily shifted. A 'thick' solution, like water mixed with a lot of nutrients, or super hard well water full of minerals- is harder to shift and will have more effect on soil ph.

Clean rainwater, at least where I live, is about 5.6 ph. It would be neutral (7 ) but it picked up a little carbon on it's way down. Even though 5.6 looks quite acidic, the ppm of rainwater is so low, its so weak, that's its ph is incredibly easy to shift.

Over the years though, acidic solutions, including even rainwater, will acidify your soil and thats why every once in a while gardeners will mix a little lime in their soil.

But for an average grow using fresh soil, if you have a decent well made soil, you shouldn't need to worry about the ph.


This obviously isn't specific to cannabis and probably any decent gardener, of which I'm not necessarily one, would know this stuff.

So stoners- go buy a book or two. Not you braink sounds like you already did.

[Nartak]

Brilliant post Weasel!! I have been following this chart bouncing from 5.9 to 6.1 in my hydro in a 2 week timeline and then i change the water so round we go again!!Thanks for clarifying a few points i was missing there man,appreciate the effort!

[Weasel]

I grow soilless mainly, and some DTW hydro - which uses a different range than soil obviously but most of what I said above applies because in general pH rises in the rootzone. Not for the same reasons necessarily. The reason for this (I think) is partly just that the plant 'eats' the acidic nutrients, and the more it eats the more the pH returns towards neutral. I think there might be other processes at work as well causing the pH to rise. I'm not sure of all that now happening in there, but I do know that, in my grow, the pH rises in the rootzone.

I did a test run once where I grew one clone at 5.2 pH and one at 6.2 pH. Same age clones in Sunshine Mix (peat moss) with identical feeding levels. After a month the plant on 5.2 was just bursting with health while the one grown at 6.2 was sickly, with curled leaves, and quickly became half the size of the other one. I threw out the 'high' one and flowered the ph-low one.