Nutrient frequency question.

[DrDee]

Hi everyone,

I've been a dirt farmer off and on for some thirty years. Finally this year I've decided to make the move to hydro. So far I've done some plants using wicks which worked quite well, and I have one plant running as a test using the Hempy bucket concept. In case anyone hasn't heard if it, it's the essence of hydro simplicity...a bucket with a hole drilled in the side 2" up. Fill it with whatever media you like...I'm using hydroton. And add nutrients daily till it flows out the hole. No aeration, no pumps. The roots go down into the 2" of solution and suck the solution up before it can go bad. Hempy has been using this system since the 80s and claims no root rot problem. My little test plant is doing well.

 

So here's my question...people determine the frequency of feedings for an ebb and flow by how much the pots dry out. If three times a day isn't enough...go to four. Well if you increase the number of floodings, isn't the plant also getting an increased amount of nutrients?

 

So technically shouldn't a person decrease nutrient strength if you have to feed 5 times a day and increase the nutrient strength if they are only flooding twice? So that the plants get access to the same amount of nutrient in any given day.

 

When that question occured to me, I realized that this is much more an art then it is a science unless I'm totally missing something obvious.

 

I need to be set straight on this issue...

DrDee

Edited January 31, 2008 by DrDee

[nouseforaname]

hey,

Changing the watering cycle doesnt mean you need to change the nutrient levels.. the plant will still only uptake as much as it wants or needs...

[DrDee]

Hi Cloner,

 

If the plants will only take up what they need, then how does overfert burn occur? It occurs because the plant takes in too much and toxifies ittself.

 

I understand that people don't change nute strenth on the basis of frequency of feeding. What I don't understand is why not?

 

Dee

[DrDee]

Hi ppl,

That was sort of a poorly thought out question I posted so I'm not surprised that there wasn't much response. I'm new to hydro and some of it is still a major mystery to me.

What I've got going on is one ebb and flow tray and a whole gaggle of plants of various strains and various size pots. I'll post a few shots here...mostly because I wanted to test out my new upload capability...Thanks big time Pure!

 

The e&f table is 31" square and filled with 24 white widow clones. With some advice from Al-B Fuct, I'm improved my operation and the plants are larger now but this was their beginnings.

 

The second shot is the rest of my plants after they were first moved to my flower room. I was hoping to do some crosses so I planted a wide variety (two mixed seed packs) and among those plants is: SwazixSkunk, Top 44, one Buddha's sister, Haze, Thai-tanic and Maroc. As luck would have it, I only got 5 males out of the whole batch and not the ones I was hoping for. If I had been trying for all famales, I'm sure I would have gotten more males! Isn't that Murphy's law...if something can go wrong, it will.

 

I may start a more formal grow report but I just wanted to add some shots and a little more info for anyone who happens to stop by.

 

Peace,

Dee

[Frazz]

Good o Dr Dee them critters look healthy enuf ... interesting Q you posed Re: nute strength and i beleive Cloner is right , and i reckon the roots will only take up as many nutrients that they can use , yet when the nutrient concerntration is too strong it actually 'burns' and shocks the roots and results in 'burning' of leaves .. i know that is not a good explanation but its the way i understand it ...

sorta like when we sunbake in the early morning when the sun is low and the rays are not high in uv we dont burn , but try sun exposure @ 3 pm and we 'burn' cause the concentration is too strong and we turn red .. thats prolly a crazy analogy but hey im no botanist

 

and also when/if i grow through summer indoors it gets really hot in my G-room like in the 30-40s, so i water more frequently and before i turn the lights off i water the plants with plain PH adjusted water, more to stop the build up of nutrient salts in the medium than anything else .. ive not heard of anyone else doing this , but the plants seem to enjoy it and i hand water so its easy and its ok with me

 

[DrDee]

Hi Frazz,

It was one of those stoned moments when I started this thread. It just seemed so logical to me that with more frequent floodings, I'd need weaker nutes. You and cloner are on the right track. What I realized later is this: The frequency of watering is determined by how much the medium dries out. And that is determined by the water retention capability of the medium. So if you only water twice a day...it's because your medium is retaining nutrients and and the plant roots are not only being exposed during flood time, but throughout the day. So it's a balancing thing that works out perfectly and allows us to maintain the res at one specific concentration. Hope I explained that OK...it seems to make sence to me.

 

I changed my medium...I had left the vegging medium in place (coco) but it was retaining too much moisture and I had to laboriously bare root 24 plants and put them in straight hydroton. Now, since the hydroton doesn't retain moisture long, I feed for 15 minutes five times a day and the plants are loving it. There was a little valve that came with my pump that had an air tap built in, so I took that baby and hooked up an aquarium air pump to it and hooked it up to the same nutrient pump timer. It bubbles air into the tube and up into the E&F tray and puts the oxygen right where it needs to be and when it needs to be there. So I don't keep a 24/7 air pump in the res. So far very stable pH. Al_B thinks it's not enough aeration but I'm giving it a run this way. My plants are almost twice the size of when that shot was taken.

 

Thanks a lot for stopping in. It's all about sharing experiences, good and bad...

Peace,

Dee

Edited February 14, 2008 by DrDee

[RobbieGanjaSeed]

So this hand watering pot idea with a hole 2 inches up...how is it going?

 

My first hydro grow was similar. Only I used stadard pots and hand watered until they leaked out the bottom. I'm on a disability pension, so I was home to do this several times per day. I had no ph meter, or Ec meter, and only one part nutrients. I used 40% flock and 60% clay balls. I was stunned how easy it was, and often use this as a model for anyone asking how to kick off.

 

I've used several recirculating systems since then, but to just get over that initial fear of going from outdoors to hydro inside, it was a great in-expensive, simple way to wet the toes you know?

 

But your idea withthe hole 2 inches up...it'd save them having to be around all day. If you think it's a goer, I'd remember it to tell others. Youi still happy with it?

 

Let us know how the harvest is will ya?

 

cheers

rob

[SukonmiSkunk]

the tip burn will usually happen when the PPM levels go above the 2000ppm mark.. this happens for various reasons.. water evaporation from hight room temps.. or mainly just the plant taking water... i find at the end of flowering the plants seem to drink more water than anything else..

 

im using hydroton in my room.. but in a recirc system in pots.. i feed 30mins on.. 30 mins off... mainly because the when the plants went in they seemed to have needed then more frequent waterings.. i suppose now that theyre are well established i could go 30mins on 60mins off.. .but they seem happy so ive let it..

 

regardless of how frequent you water.. the PPMs will need to be around the 14-1800 mark.. just make sure it doesnt venture to far above that... everything should be fine..

 

looking at the pics, looks like everything is going along perfectly.. so until you notice problems with the leaves, id be just plodding along as you have been.. they do look real healthy..

 

[nouseforaname]

hey,

Heres my brainfart for day inspired by Frazz

thats prolly a crazy analogy but hey im no botanist rolleyes.gif

Depending on your medium... you could group them into high water retaining (spongey) substrate and low water retaining (rocky)substrates..

rockwool retains the most water.. then cocofibre.. fytocell these all hold tonnes more water than any of the following (perlite, clay and vermicultite) they all drain at different rates aswell.

 

So lets say we have your standard pot size(8") with a saucer under .. of each of the mediums above all filled with the 6 different mediums the plants would all still use 600ml - 1 ltr of water for each medium over the period of the day...

 

the rockwool coco fyto could all be handwatered once a day allowing the runoff to pool under in catch tray without hassles..

The perlite clay and vermiculite would need enough watering for it to uptake the 600ml - 1ltr this may be the same litre of water recirulating past the roots 100 times a day because when you water 95% runs off... ( this making any sense???)

 

Now depending on your position in life and amount of time you have for your hobby, helps to pick the substrate or medium for you...

 

 

Has anyone else tested or trialed to try find the right combination for them???. Personally think plants like 30% wet / 70% dry cycle meaning from time they are watered being 100% wet to when they are rewatered the medium retains 30%... have also found that mixin one from the spongey and one from the rocky substrate side is usually more user friendly .. Another good idea is a layer of rocks at base of pot...

 

( coco/perlite, clay/coco, rockwool/clay , fyto/perlite) mixs have all worked fine

 

no special research for this other than watching my plants... Hope that enlightens you some

[RobbieGanjaSeed]

Now depending on your position in life and amount of time you have for your hobby, helps to pick the substrate or medium for you...

[]

 

I had fuckin tears in my eyes reading that.. you ought to do more creative writing mate.

 

The question I always get hung up on is "given all day long and nothing to do, which is the best to use?", making choosing a medium the most conflicting morally I have. Am I lazy, or am I active?

 

Seropusly, I wonder all the time what's the best to do, use wet material and expose to water all day, constantly allowing a steady flow of nutrient, or drying out several times a day, enjoying the benifits dirt plants flourish with, that being exposed to lots of air.

 

Ideally, in a dream world, I'd like a medium that dries out 4 times a day, with me catching it at peak oxygen exchage. but how do you find this point? How do you know when meax. oxygen exchange is taking place, verses overdrying of medium.

 

yer right Dr. Dee, shouldn't think on this stuff bent.

My old uncle always said, "never fuck with ya computer or ya fish tank after a joint". he said you'll either fuck yourself with one or the either.

Sounded deeep at the time. But it isn't. At the same time it has some great advise in it somewhere...

 

rob