Specific amounts of water for growing.

I've been noticing this more recently.. people watering their plants an exact measurement of water like 200 or 600ml or 6 oz. of water.. and doing it daily!

What is the deal here!?!? As far as i've known that's NEVER been the proper way to water a plant. Keeping a constantly moist soil medium is a BAD thing to do.
So where the hell did this old wive's tale come from??

You always water for the size of the plant, not the size of the pot.

Is that what has been mis-understood?

Comments..

Discuss!!

Bob.

i have lots of videos and guides and the general idea is to water every day, one says to water 3 times a day, one says to water 200ml a day, another says to water untill the water drains out the bottom do this every 2 days. Thanx to bob i now know this is wrong coz of the green perlite!

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Originally Posted by Pezzo

another says to water untill the water drains out the bottom do this every 2 days.

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That sounds much more reliable and less likely to give you moss growing on the top of the soil medium.

I've always understood that having a consistantly wet medium is a BAD thing, for seedlings, vegging plants and flower.. If anything as the plant grows you spread the watering out even more.. going from 4 or 5 waterings a week down to two or even one watering a week with a larger plant.

The larger the plant, the more water it's going to be absorbing.

Watering so that water comes out of the bottom of the pot would also ensure that the roots are growing down and using as much of the soil medium as possible.

A consistantly wet soil medium with seedlings can cause what's known as "damping-off".

Bob.

kl thx, i always thought seen as seeds germinate in wet conditions and clones grow roots in wet conditions that seedlings would get a boost with wet soil. o well ones growing :)

seeds germinating in wet conditions are prone to 'damp-off', or Pythium Wilt ... all 'expert' opinions I have gathered over the years, call for a well-drained soil, and letting the plants go through a "wet/dry" cycle ... letting the soil dry out well, between waterings, just like in nature ... the roots cannot 'breathe' in constantly damp soil, and growth will be slowed, or worse ... this, according to botanists, and a whole lot of people LOTS smarter than me ... :D

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Originally Posted by the image reaper

seeds germinating in wet conditions are prone to 'damp-off', or Pythium Wilt ... all 'expert' opinions I have gathered over the years, call for a well-drained soil, and letting the plants go through a "wet/dry" cycle ... letting the soil dry out well, between waterings, just like in nature ... the roots cannot 'breathe' in constantly damp soil, and growth will be slowed, or worse ... this, according to botanists, and a whole lot of people LOTS smarter than me ... :D

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Horticulture is a beautiful thing.. literally!

Misting the leaves with boiled water will also allow the humidity to be kept during the "dry" days. I say boiled because boiled water is not only sterilized but tends to not leave water marks on the leaves if the water is hard (which it usually is)

But don't take my word for it..!

Bob.

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Originally Posted by Bob
I better not find out you use MiracleGro.

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whats that about bob?

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Originally Posted by Pezzo

whats that about bob?

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LoL you need to ask?

It's more a joke than anything.. but seriously... don't use miraclegro..

y? thats what im using lol

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Originally Posted by Pezzo

what has two words and is something everyone on this forum should use?

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Search Feature!

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Originally Posted by BobBong

You always water for the size of the plant, not the size of the pot.

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I allways water for the size of the pot .... why???As long as im sure that drainage is good, the time between waterings will be longer and the work of carrrying lots of water will happen less frequently...also i´m not saying that if i have plants in 3 gallon pots i´ll water them with 3 gallons i´m just saying that the size of the pot is my reference...also i find that since i started using this method the plants roots have grown not only across the areas where usually water and air pockets can be found but in a very well distributed scructure all around the pot...i do this NO MATHER THE SIZE OF THE PLANT!!!!!!!!!!.....but when i say this i allways add......POTS MUST HAVE EXCELLENT DRAINAGE!!!!!!!!...and of course that many other stuff is related to the watering issue...heat, humidity, airflow bla bla bla have a huge impact on a how u should water ur plant...imo u just need to pay atention to the plants, before all this high tech grow gear that we have today the growers had no more that the knowledge of experience and they did just fine....well im :stoned: :stoned: so ill check back later to find out more about what goin on in the water world..Peace and Pot

....I used a cheap 4 dollar..moisture meter...water- when dry reading shows...don't water again..until another dry reading shows...I follow the K.I.S.S. principle

i fully agree with letting them dry out a bit.
i have however quoted on another thread that my seedlings are taking between 30-50ml twice daily...they are in small pots under an HPS and dry out fast....the pots wigh pretty much nothing when i water them.

watering really is just somthing that you get a feel for, the more you grow.
everyones heat/drainage/soil(retention)/plants will be different so, to say that a plant/pot thats a certain size needs "x" ammount of water daily isnt really a very good guide.

moisture meters are a really good idea, i use one myself now and then or just to double check, but after a while i can just tell, its like a sixth sence that developes lol

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Originally Posted by BobBong

That sounds much more reliable and less likely to give you moss growing on the top of the soil medium.

I've always understood that having a consistantly wet medium is a BAD thing, for seedlings, vegging plants and flower.. If anything as the plant grows you spread the watering out even more.. going from 4 or 5 waterings a week down to two or even one watering a week with a larger plant.

The larger the plant, the more water it's going to be absorbing.

Watering so that water comes out of the bottom of the pot would also ensure that the roots are growing down and using as much of the soil medium as possible.

A consistantly wet soil medium with seedlings can cause what's known as "damping-off".

Bob.

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Hi Bob, can you clarify this for me... Watering the plant until it comes out the bottom takes Microorganisms and nutrients out of the medium. So in your opinion, what benefit does this serve?


Wet and dry cycles are very over rated in my opinion, because there is a certain amount of oxygen in the water your applying, albeit making up 1% of plants needs. Take for example Tranobles grow, he water's a certain amount that varies according to the plants life cycle. He dosen't flood and drain the soil from what I remember. He gets fantastic results, granted the room is sealed. Just like to hear some technical/scientific arguments why wet and dry cycles are better than precise amounts. Although water logging is a bad thing, I don't see the importance of trying to mimic outdoor conditions, seeing as all other conditions are subject to the growers intervention. I think that if you take some Hydrophonics systems as an example, the root ball can sustain themselves in water almost completely submerged without being suffocated. I think its a fallacy to assume that you can drown roots in a soil medium because the soil just is not saturated enough to devoid the medium of oxygen. You would have to water log the entire medium consistently to kill the roots.

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Originally Posted by MegaOctane12

Hi Bob, can you clarify this for me... Watering the plant until it comes out the bottom takes Microorganisms and nutrients out of the medium. So in your opinion, what benefit does this serve?


Wet and dry cycles are very over rated in my opinion, because there is a certain amount of oxygen in the water your applying, albeit making up 1% of plants needs. Take for example Tranobles grow, he water's a certain amount that varies according to the plants life cycle. He dosen't flood and drain the soil from what I remember. He gets fantastic results, granted the room is sealed. Just like to hear some technical/scientific arguments why wet and dry cycles are better than precise amounts. Although water logging is a bad thing, I don't see the importance of trying to mimic outdoor conditions, seeing as all other conditions are subject to the growers intervention. I think that if you take some Hydrophonics systems as an example, the root ball can sustain themselves in water almost completely submerged without being suffocated. I think its a fallacy to assume that you can drown roots in a soil medium because the soil just is not saturated enough to devoid the medium of oxygen. You would have to water log the entire medium consistently to kill the roots.

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With hydro do you not use an air stone?

The idea of watering until it comes out the bottom ensures that the roots will be growing down to the bottom of the pot, using as much of the soil medium as possible for the root ball. It also ensures that the nutrients you add will saturate the soil and fully feed the plant.
Also, by the act of percolation the built up salts will head to the bottom of the pot making it that much easier to flush them out when the time comes.

In reality you CAN water any plant a specific amount of water, as long as the roots are getting what they need, the humidty of the medium isn't maintained at a high level and the ambient humidity isn't affected.
Generally, this involves leaving a few days between each watering to allow for the water to at least begin to dry up.
You do however want to promote the growth of the roots to the bottom of the soil so that the rootball is larger.

Interesting opinions on this. Non are really wrong.. but it is best to know what is needed when watering our plants.

Thanks for that Bob. I've come to the conclusion that wet and dry cycles are probaly the safest and easiest option, although I haven't found too much scientific information to suggest that measured dosage is more beneficial. I'd thought I'd post this because I found it interesting and its for anyone else who wants to know.

Plants, obviously as a by product of photosynthesis produce oxygen so that they have relatively easy access to oxygen during the daylight cycle. The roots on the other hand have a much harder time to utilise enough oxygen for their requirements. This results in restricting root respiration, which in turn slows photosynthesis, which in turn reduces the growth of the plant. Consequently, the happiness and the potential of the plant are very dependant uopn the roots securing enough oxygen. Plants are only able to grow as well as the roots allow it ; yeild can be directly measured in proportion to the root growth. Warm water holds directly less oxygen than the cold water, however, very cold water can be detrimental to the plants, effectively, shocking the root system until the water warms up enough for the plants to get over this shock. The colder and fresher the water, the more oxygen content ; the warmer, the less. Approximatly 0.0014% of dissolved oxygen can be found in very cold, fresh water. Approximately 0.0008% of dissolved oxygen can be found in fresh water at room temperature and water at room temperature is exactly how the plants like it. Heating your water too much can be very detrimental to your plants potential.

Oxygen obtained via the roots directly from the nutrient solutin only makes up 1% of the plants needs. So oxygen supplied via the nutrient solution is only a minor source supplied to the roots. Aerating the nutrient solution will help, however, this mainly serves to kill off any pathogens, basically keeping the nutrient fresher for longer. So you can see that allowing the plants some dry time will server to get more air to the roots. Even in aerophonics, which delivers a highly oxygenated solution directly to the rootball, it is essential to give plants dry time (at night for example) to allow air to reach the root system. Another tequnique is to add H202 to the reservoir, which again , due to its extra oxygen atom, increases the dissolved oxygen in the reservoir. However, when H202 is diluted, it becomes unstable and soon breaks down and dissolves completely into the reservoir, so it normally will only oxygenate the reservoir for a few hours. Also, when H202 is regularly administered to the reservoir, it keeps the nutrient solution fresher for longer. However, overdoing H202 can be very detrimental to the plant's roots. In high doses, it attacks many usable food chains that the plant will be deprived of.


Highly oxygenated root systems benefit from another very important fact. Oxygen manipulates and effects the electrical charge found in water and for that fact, nutrients. This changes in electrical charges allows roots to uptake water and nutrients with a lot less energy compared to non-oxygenated root systems, so clearly roots benefit from as much oxygen as you can provide them. Properly aerated solutions will absorb up to 0.0008% oxygen and hold it for up to 24 hours.

Share the Knowledge

thanx 4 the info but i thought plants used up co2 and gave out oxygen so feedin it co2 would be more benificial wouldnt it?

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Originally Posted by Pezzo

thanx 4 the info but i thought plants used up co2 and gave out oxygen so feedin it co2 would be more benificial wouldnt it?

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Co2 can only be used in HID lighting and generally requires an enclosed , relatively airtight area so that you can raise the Co2: o2 ratio. However, this is only needed if you have an enclosed area with high concentrations of o2 (or a lot of plants).

Co2 is only utilized properly by advanced growers who know what they're doing.

a lot of plants - like 10 plants ina 3'sq area?

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Originally Posted by Pezzo

a lot of plants - like 10 plants ina 3'sq area?

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And airtight? ... yea.. something like that. You basically would have enough Co2 in the air simply by living in the same house as the plants. If the grow room is airtight.. well, that's different.

my room isnt air tight but itll be full wiv plants

mite get some pic, brb

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Originally Posted by BobBong

Co2 can only be used in HID lighting and generally requires an enclosed , relatively airtight area so that you can raise the Co2: o2 ratio. However, this is only needed if you have an enclosed area with high concentrations of o2 (or a lot of plants).

Co2 is only utilized properly by advanced growers who know what they're doing.

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And also you need ALOT of light, because lumen intensity is directly related to c02 uptake.

hey sorry i took so long, cannabis.com cut out when i uploaded the pics and i deleted the pics off my pc, then i went out, then i had to get more pics and upload them...

http://gallery.cannabis.com/showgall...0&ppuser=58578

my flowering area is the same except wiv a 400 watt HID HPS light in it!

The question was asked on this thread why water until you have water run off coming out the bottom of the pot? Well for one to make sure you have no excessive dry pockets and to help to promote greater and more evenly spread out root growth that is not bunched up in the upper and middle portion of the pot. The roots will follow the water and reach towards the source and when you have water making it's way to the bottom of the pot it causes the roots to grow down towards the bottom as well as the sides and the middle of the pot. Healthy, strong and large root balls equals good harvests.
Also to maximize the room in your pot different mediums can be placed on the top of the soil such as washed and rinsed lava rock, garden type stones and even marbles for some to help the top soil to stay moist longer in order for roots to grow up as well as down making the most of your pot size. The medium on the soil stops the top of the soil from drying up so quick, which causes the roots to shy away, and also the really dry top soil causes the impact of water to be rougher when cutting threw the water to the roots, with the medium on top the water flows over the medium allowing for a slower and wider distribution of the water rather than having the water just cut into the soil, also as the water flows threw the medium it generates small but beneficial amounts of O2 which is pulled down to the roots in the water.
Hope this helps some.

y does everyone water their plant from the top? water from the bottom man.

Anyone wanna argue wiv that?

^^^ Wow that got a lot of feedback lol, cmon ppl what u think?