EC, ph & water levels. What they tell you and how to react.

[Woody J]

This table is not meant to be exhaustive. It is primarily for use in conjunction with DWC & variants or any other hydro setup where you have an air stone. The main complication is the acid rain effect in Note 1 below. This does not apply to waterfall effect or flooming for introducing Dissolved Oxygen.
Its intention is to give anyone suffering ph, EC issues in DWC and variants some idea of the different solutions to the various states you can have.
There are 18 different states you can get in DWC and though many have common solutions, such as a falling EC, which is usually a good sign could mean a slight raise in EC may be needed. However, this depends on the state of the other elements. For example, if our falling EC is accompanied by a falling ph too, this suggests a res change due to either acidic nutrients or ph- or the acid rain effect (note 1) causing the ph to drop.
The first thing to check in any of these scenario's is the meters being used.
Make sure they are calibrated. If you can, check the readings against a second meter if things dont improve after making changes.
As a general guide, if the ph is between 5.8 and 6.2, do not rush into changing anything unless your plants are displaying symptoms of a problem.

In DWC, a good safe EC is around 1.2 to 1.4, I have rarely seen problems with plants fed at this level.
These levels are for healthy maturing plants either just before placing in flower or once into flower. For smaller/younger plants adjust EC accordingly, starting down at around 0.4
This is exclusive of any background EC. So if your source water has an EC of something like 0.5, work with an EC of 1.7 overall. As always, use judgement in finding the correct EC for your plants. This will vary by plant depending on the stage of growth. DO NOT jump in with seedlings of freshly rooted clones with an EC of 1.7, you will kill your plants.

I am also assuming grow media have been washed/rinsed/buffered properly in ph'd water.
Most media (inert) should be soaked in water with a ph of around 5.8 for 24 hours. This tends to help prevent later ph fluctuations.
Water level EC pH Solution
Static Static Static Plant not feeding/drinking, change EC, check meters. Usually, lowering the EC a little should get the plant feeding again
Static Static Rising Ph buffers probably raising ph. This is usual. Having a static water level is not though, so again, a slight reduction in EC or a res change should resolve this.
Static Static Falling Usual cause of this is when media has been rinsed at a lower ph than you require.
The other possibility is that too much CO2 has been pumped into the water. See Note 1.
Change your res and look at the volume of air pumped plus look at your air source.
Static Rising Static Plant is leeching nutrition, raise EC. Note 2
Static Rising Rising Plant leeching nutrition, Raise EC. An unusual state. The rising ph is probably caused by what nutrient leeching back.
If these are alkaline, it will lead to the rise in ph. Could also be ph buffers.
Static Rising Falling As above but be aware of the acid rain effect mentioned in note 1. Res change, plus increase in EC.
Static Falling Static Plant eating but not drinking. Not ideal. Lower EC or res change
Static Falling Rising As above but rising ph is a better sign. Lower EC slightly or res change.
Static Falling Falling Falling ph along with falling EC but no drop in water level suggests a res change. Could also be an acid rain effect as per note 1. Depending on other symptoms, lowering EC after res change.
Falling Static Static Perfect conditions. EC and ph are at the correct level.
Falling Static Rising Normal state most people encounter. Nothing to worry about, carry on doing what you are doing unless other plant symptoms.
Falling Static Falling Res change plus a change of EC. Lower EC if over 1.4, raise EC if lower than 1.0
Falling Rising Static Plant is drinking more than eating, lower EC.
Falling Rising Rising Plant is drinking more than eating, lower EC
Falling Rising Falling Plant is drinking more than eating, lower EC. Also, res change due to possible acid rain problem.
Falling Falling Static Hungry plant, raise EC. Very good situation to be in. Nute buffers are working and plant is taking a balance of nutrients.
Falling Falling Rising Almost as above, usually considered almost perfect, raise EC slightly.
Falling Falling Falling Res change. Potential acid rain issue but plant is still eating & drinking. Raise EC on new res.

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.
Even a moderate plant that will be yielding 3 or 4 oz should be going through 3 or 4 l of water per day. I have seen me giving larger plants as much as 10l per day food & water, its like keeping a horse! But you cant smoke a horse :P

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!

If you disagree with stuff in this post, please PM me. I do not want this thread to end up as a big debate or argument. I am hoping people take it as an honest attempt to help those suffering issues in DWC. The info in this post is my opinion. Before taking any corrective action based on this post, please double check.

[jimmi420]

Good post m8.

[Murdock]

good shout woody, those ec levels for dwc are around the same i use in nft , submerged roots in a costant flow of nutes don,t need high ec levels,

[Friday]

Awesome thread woody :)
Cheers for going to the time to put it together for us mate - it'll help me out and many more I'm sure.
:)

(Defo sticky material Mods :))

Cheers again W.


Friday :D
http://www.thctalk.com/cannabis-forum/showthread.php?85437-Friday-Scrog-s-AK47-Serious-Seeds-Grown-in-Coco-Autopot-Styliee-%26%23128523%3B

[Woody J]

Hi, I have made a mistake on the note 2 section. Where it reads
"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. "
2 lines from the end of note 2, it should read
"If however, the EC of the solution is lower than the "internal EC", then the balancing will work the other way and nutrition will be leeched from the roots to the solution. "

Sorry for any confusion this may cause.
Thanks to Friday for spotting it.
I hope there are not many more lol.

Thanks to all for the thanks. I had promised to write this up after a couple of guys had issues of falling ph. I hope this explains why and how to solve.
Stay safe guys.
W

[Rory Breaker]

Nice one Woody.. this should be a sticky for sure :)

[spoonofinsanity]

nice one woody i've already linked it to a diary where they are struggling with ph drop in dwc hopefully this will help the op sort it :)

[Upton]

Great stuff mate. Worked for me and still is :D

Sent from my GT-N8010 using Tapatalk 2

[kidwao]

Great post, thank you for that.

Though I think I found one little typo. Note 2 paragraph 5.
I think you meant: So if the EC of the nutrient solution is lower than the "internal EC", then food & water will flow from the solution to the roots, this is the normal process.

[Oxy]

sticky well worth a read cheers woody

[waterdawg]

Thanks woody I pasted it to the "important pot stuff"!!! I do struggle with the PH thing.

[jamiesmoke]

thanks for the info :)

[Super_Stout]

Great info mate, sticky..

[newfarmer024]

Thanks for the info woody!

[RastaMouse22]

Awesome guide there pal :D will most definatly come in handy for me.. job well done :bigjoint:

[SuperLemonTony]

Nice thread... Thanks for this.

[RastaMouse22]

Sticky maybe? Mods? :bigjoint:
Found it very usefull :)

[Oxy]

think i got it at last mr woody, thanks cheers for the help without people like you lot knooobs like me wouldn't be teaching you a thing or to in the future hahahah ta

[kellypinto]

How many of you use tap water right from the hose as oppossed to letting it stand to evaporate the Chlorine?

[Dr.GreenThumb420]

How many of you use tap water right from the hose as oppossed to letting it stand to evaporate the Chlorine?

You really should let it sit, and I used to... But this run I've been going straight from my faucet to my DWC

[Upton]

If you use bennies then let it sit for 24 hours otherwise don't bother :)

Also why isn't this a sticky??

[Dr.GreenThumb420]

If you use bennies then let it sit for 24 hours otherwise don't bother :)

Also why isn't this a sticky??
Did so with the great white and didn't seem to affect how the GW reacted in my bucket... Cleared up the algae and roots look white and healthy as shit... Maybe I don't have much chlorine in my tap...not sure but I haven't noticed it affecting anything

[Upton]

I thought it was common knowledge that chlorine kills the micro heard... maybe i'm wrong???

[Dr.GreenThumb420]

I thought it was common knowledge that chlorine kills the micro heard... maybe i'm wrong???

No, you're probably right. I was just saying that's what I did with the product still doing its job... That being said, my stoner ass didn't even think of the chlorine killing it(which is why it's added to city water) so from now on I'll be letting water sit out with an airstone running in it

[Upton]

You could also add some molasses to feed the heard now all the algae has gone :)

[Dr.GreenThumb420]

You could also add some molasses to feed the heard now all the algae has gone :)

How much per gallon would one use? I'll pick some up at the store today... Is there a specific type of molasses?

[Upton]

I'm using 20ml of Meridian Organic Blackstrap Molasses (unsulphered), 3/4 of a cup of earth worm shit and a spoon of Great white to 10ltrs of water, which I bubble for 48 hours. I strain the mix through a filter to remove the crap and then add 500ml to my 30ltr system.

I've also been adding a squirt of liquid seaweed to the mix and have a sponge in the res to give the bennies a home.

Sent from my GT-I9300 using Tapatalk 2

[platinum_rouge]

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!



I couldn't have said it better. If people took on board this one bit of information that plants dont need to be kept in high EC environments to thrive then there would be a lot more tasty smoke knocking about. Hat off to your excellent advice sir

[Humph]

what a cracking read thanks mate!

[stealthgrow]

Does this not work for RDWC when you are flooming ??

what would be the big difference ?

[Hannibal]

None at all even more so in RDWC as the roots are in contact with their food. Keep your ec on the lower side rather than too high.

[stealthgrow]

read this on the first couple of lines in the post "This does not apply to waterfall effect or flooming for introducing Dissolved Oxygen" just read it agian and it must have been referring to acid rain effect ??

Cheers H - copied into my noob book :cowboy:

Brilliant post cheer ears

[Hannibal]

It was all about how ph of water becomes acidic when pumping air into a system through airstones.

[jonnyfive]

Hope you don't mind Woody, but I found the table a little hard to read so have reformatted it.



Water level
EC
PH
Solution


Static
Static
Static
Plant not feeding/drinking, change EC, check meters. Usually, lowering the EC a little should get the plant feeding again


Static
Static
Rising
Ph buffers probably raising ph. This is usual. Having a static water level is not though, so again, a slight reduction in EC or a res change should resolve this.


Static
Static
Falling
Usual cause of this is when media has been rinsed at a lower ph than you require.
The other possibility is that too much CO2 has been pumped into the water. See Note 1.
Change your res and look at the volume of air pumped plus look at your air source.


Static
Rising
Static
Plant is leeching nutrition, raise EC. Note 2


Static
Rising
Rising
Plant leeching nutrition, Raise EC. An unusual state. The rising ph is probably caused by what nutrient leeching back.
If these are alkaline, it will lead to the rise in ph. Could also be ph buffers.


Static
Rising
Falling
As above but be aware of the acid rain effect mentioned in note 1. Res change, plus increase in EC.


Static
Falling
Static
Plant eating but not drinking. Not ideal. Lower EC or res change


Static
Falling
Rising
As above but rising ph is a better sign. Lower EC slightly or res change.


Static
Falling
Falling
Falling ph along with falling EC but no drop in water level suggests a res change. Could also be an acid rain effect as per note 1. Depending on other symptoms, lowering EC after res change.


Falling
Static
Static
Perfect conditions. EC and ph are at the correct level.


Falling
Static
Rising
Normal state most people encounter. Nothing to worry about, carry on doing what you are doing unless other plant symptoms.


Falling
Static
Falling
Res change plus a change of EC. Lower EC if over 1.4, raise EC if lower than 1.0


Falling
Rising
Static
Plant is drinking more than eating, lower EC.


Falling
Rising
Rising
Plant is drinking more than eating, lower EC


Falling
Rising
Falling
Plant is drinking more than eating, lower EC. Also, res change due to possible acid rain problem.


Falling
Falling
Static
Hungry plant, raise EC. Very good situation to be in. Nute buffers are working and plant is taking a balance of nutrients.


Falling
Falling
Rising
Almost as above, usually considered almost perfect, raise EC slightly.


Falling
Falling
Falling
Res change. Potential acid rain issue but plant is still eating & drinking. Raise EC on new res

[champion7]

just what i was looking for brilliant info

and a happy outcome

cheers

[She's-a-Lady]

Great thread. Thank you! :D

[newbie89]

Hey guys my water level static/ec rising/pH rising. Leaves showing nute burn. Should I still raise EC? Base 0.4 ec was set at 0.6. Day 39 autos, I have a diary running, cheers for any replies.

[NatureVal]

how often do i need to check the EC/PH levels?

[GrassLeaf87]

how often do i need to check the EC/PH levels?

Every day chap!!!
I did for a peace of mind n that

[Jingo]

how often do i need to check the EC/PH levels?
I check everyday till I knew how things were going. After that I only check every few days. Once you know your set up you don't really have to check every day in my opinion.

[redisiel]

Everyday without fail if I can't the missus will things can change so quick I wouldn't risk it and it takes a minute and on average they need a top up anyway later on,
Atb
Redz

[tizzay]

Dwc in a nutshell :p

Sent from my HTC One_M8 using Tapatalk

[Hogweed]

Guys… if people are still reading this thread, here’s what’s really confusing me. I have hard water, EC 0.6.

Now, my understanding is that EC itself is simply a way of measuring the amount of nutrients in the water – nitrogen, potassium, phosphorus etc. The more of them you add, the higher the EC. OK.

But my confusion comes from advice on various forums and guides telling me that I have to include the natural EC of my water in the total.

Now I think that means, if I want an EC of 1.8, I’m already starting from 0.6, so I just need to add enough nutrients (Canna Vega at this stage) to give it an extra 1.2.

That’s simple enough, except… the 0.6 of the water is caused by different salts (mostly calcium and magnesium, I think) from the ones in the Canna Vega, eg NPK, which the plant needs to grow. So if I only add 1.2 of Canna Vega to achieve a total EC of 1.8, the composition of my growth medium will be very different than if I’d started off with (say) distilled water, and added a lot more Canna Vega to bring it up to the 1.8.

What am I missing please?
Thanks

[redisiel]

Your not missing anything mate, try not to overthink it.
Just go by the ec on whatever water you will be using and you are going to start feeding at a certain amount and up it as needed. Just worry about the water you are using.
If your going to use RO or distilled it's a different story all together because there's a lot more to it than the calcium and magnesium there's lots of trace elements.

Your background is not far off mine 0.7 and I also use vega and all seems to be great
Atb

[Hogweed]

Sadly, being a touch OCD, not over-thinking is not an option with me, so what I try to do is at least make the excessive analysis bear fruit! OK, so whatever my water starts off at, if the feed manufacturer recommends 1.2, I should simply add nutrients till I get to 1.2, and take quiet satisfaction from the fact that I only have to use half as much feed as somebody who starts off with water which is 0.0 (if there were such a thing)…?

I’m seriously pissed off with the pH meter I bought (pic attached – avoid). First one wouldn’t calibrate properly as they hadn’t supplied the correct sachets for hard water. They sent me another complete meter, with the correct sachets – but both meters calibrate very differently with the same sachets, so I don’t know which (if either) to trust.

So the mixture appeared to jump way up into the 7’s, I put a drop of phosphoric acid in, and it went down to 4.4 FFS. So I’m using the other meter now, as I think the first one was reading too high, and have managed to get the pH back to 5.8.

Seems like a hell of a faff though… maybe I’ll grow in soil or something next time!

[redisiel]

Don't worry.
For one as for nutrients forget how much the bottle says.
You want to start at a low feed so like I say just go by your water your using, I'm going to flick back and see where we're at again sand sub to the right diary.
We do want to sort the ph meter though.
The last one you used you said it collaborated properly right?
and ph down is strong shit I would do that a drop at a time if I were you mate
Blessings
Redz

[Hogweed]

OK I've figured one meter is OK, the other one's fucked, so using the first one at 5.8.

So my total feed (including the water measurement) is coming up at 0.88 - I know you're saying forget how much the bottle says, but the Canna Aqua Vega site says I should be on 1.1 + 0.6, ie 1.7... seems a lot more than were I am...?

[redisiel]

Ok my background ec is 0.8 so I started my lady's on 1.2 that means there first feed was 0.3. We are going to let the plants tell us when to up it you can even start at 0.2 if you like. And we want to see the ph either stay how it is for now and hopefully get a slow swing up or down?
I still ain't Seen the ladies in question so I'm just basing this on seedlings/cuts going in a new system or pot
Redz

[Hogweed]

Right, I can see I'm going to have to go completely against my nature, and keep proper records...

So this morning we have pH 6.25, EC .876.

I'll do nothing till this evening, then measure it again...

Here's a pic - there's only one lady at the moment, as I'm just easing myself into this gently and as simply as possibly!

If you wanted to do it simply, you shouldn't have chosen hydro, I hear you say...

[Hogweed]

GAAAHHHHH. Just keep screwing up here. Because the pictures on eBay were the same, I accidentally bought an Essentials EC meter instead of an Essentials pH meter, so now I’ve had to order the pH meter too.

However… while the nasty little blue EC meter I had is reading around 871 (suspiciously, it doesn't seem to be moving much from there, though the plant seems to be growing strongly), the new Essentials EC meter reads 3.5!

Now, I thought the blue meter needed to be divided by 1000 to get a reading that people can understand, so I’ve believed my reading so far to be around 0.8 – 0.9. So how the hell can I relate that to 3.5 on the Essentials meter??? I’m assuming the little blue meter is talking complete shite, but of course I don’t know…

Thanks guys

[redisiel]

Hogweed mate, make it easier on yourself and keep your post in the same thread. I'm subbed up to your diary matey
Atb
Redz

[Hogweed]

Sorry, you're right. Panicking here. Will go to the other one...

[redisiel]

And a ec reads either ppm( parts per million) tds(total desolved salts) ec etc. Your going to have to sort which one you are going to use.
I'm a bit confused because I have got two different ppm readings on my truncheon I ain't got it with me on the bus but I think one is Europe and the other USA I'll have to check.
I'll check when I get back and get back to you so we can get this sorted finally
Redz

[redisiel]

Meet you there lol chill out brother I'll find ya and there's plenty help around bro
Redz

[devinrayolsen]

Even more great info for hydro farmers! Thank you

[ProffessorBubbles]

I'm wondering if Woody J is still here using this site as I'm needing a little info about my grow and From what I read and see he really really knows his shizzle so can anyone tell me if he still posts or if he hasn't been see for a while.
Thanx in advance peeps. Peace...

[M_C]

Woody J was last here March last year :(

[Rizo]

Some really good information, thank you

[toblue]

This is an old but excellent thread and I am sure Woody has forgotten more than I will ever know.

But I do struggle with his NOTE 2.

I can see it makes sense but it goes against everything else I have read. " Static water level, Nute ec going up means you are feeding to high as the plants can't take any more nutrients so don't drink, reduce ec and plants will drink more then work your way up from there.

Woodys initial post below

Note 2.

Most people assume that with a rising EC, it is the plants way of saying, I don't 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 lower 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.

[johndoh]

have put the chart into an image
you can see full chart you can now download and print.
I hope this is ok guys.

[johndoh]

sorry a pdf
so I can print it and put in waterproof sheet and keep in tent:harvest:

[marcus]

Nice to see your still around with top advice!

[Maukit]

Hi, looking for some advice .....is there any pros or cons to what one....im going to be using dwc system...thnx in advance :)

[M db]

Grande woody, thanks to you i understood what's happening to my tomats ,
I stared on a hydroponic 25L
4th week of grow i was keeping EC 1.2 PH 5.5 to rise till 5.8
boom in the afternoon EC 1.4 and ??
PH 5.3??
Whater level was down????? Panic???? i saw what you have rote ,so i add more nutrients 1.4 with 1 teaspoon of Epsom salt .
PH 5.8
Ec 1.4

and after 24 hours
EC 1.3
PH 5.6
Water drop
Plants are growing.
So next res change ill keep them 1.4.
Thanks a lot for your great explanation .

[M db]

Grande woody, thanks to you i understood what's happening to my tomats ,
I stared on a hydroponic 25L
4th week of grow i was keeping EC 1.2 PH 5.5 to rise till 5.8
boom in the afternoon EC 1.4 and ??
PH 5.3??
Whater level was down????? Panic???? i saw what you have rote ,so i add more nutrients 1.4 with 1 teaspoon of Epsom salt .
EC 1.4
PH 5.8
And after 24 hours
EC 1.3
PH 5.6
Water drop
Plants are growing.
So next res change ill keep them 1.4.
Thanks a lot for your great explanation .

[DaveB22]

Thanks for the info Woody. Hopefully I will be able to get the nutrient burn issue I have had under control on my next grow. Dave

[Jingo]

EC to PPM to CF



EC
ms/cm
Hanna
500ppm
Eutech
640ppm
Truncheon
700ppm
CF
Ballpark EC per Stage


0.1
50
64
70
1



FL


0.2
100
128
140
2



FL


0.3
150
192
210
3



FL


0.4
200
256
280
4
S


FL


0.5
250
320
350
5
S


FL


0.6
300
384
420
6
S
V

FL


0.7
350
448
490
7

V




0.8
400
512
560
8

V




0.9
450
576
630
9

V




1.0
500
640
700
10

V




1.1
550
704
770
11

V
F



1.2
600
768
840
12


F



1.3
650
832
910
13


F



1.4
700
896
980
14


F



1.5
750
960
1050
15



1.6
800
1024
1120
16



1.7
850
1088
1190
17



1.8
900
1152
1260
18



1.9
950
1216
1330
19



2.0
1000
1280
1400
20



2.1
1050
1334
1470
21



2.2
1100
1408
1540
22



2.3
1150
1472
1610
23



2.4
1200
1536
1680
24



2.5
1250
1600
1750
25



2.6
1300
1664
1820
26



2.7
1350
1728
1890
27



2.8
1400
1792
1960
28



2.9
1450
1856
2030
29



3.0
1500
1920
2100
30



3.1
1550
1984
2170
31



3.2
1600
2048
2240
32



Ballpark starting EC:
S = Seedling
V = Vegetative
F = Flower
FL = Flush


Base EC = Initial EC of water source (city, well, distilled, or RO)





EC, PH & Water Levels for Hydroponic Systems
What they tell you and how to react (https://www.thctalk.com/cannabis-forum/showthread.php?86654-EC-ph-amp-water-levels-What-they-tell-you-and-how-to-react&p=1069366058#post1069366058)
(Source: THCtalk.com (https://www.thctalk.com/cannabis-forum/showthread.php?86654-EC-ph-amp-water-levels-What-they-tell-you-and-how-to-react&p=1069366058#post1069366058))




Water
Level
EC
PH
5.5->5.8<-6.2
Solution


Static
Static
Static
Plant not feeding/drinking, change EC, check meters. Usually, lowering the EC a little should get the plant feeding again.


Static
Static
Rising
Ph buffers probably raising ph. This is usual. Having a static water level is not though, so again, a slight reduction in EC or a res change should resolve this.


Static
Static
Falling
Usual cause of this is when media has been rinsed at a lower ph than you require.
The other possibility is that too much CO2 has been pumped into the water. See Note 1.
Change your res and look at the volume of air pumped plus look at your air source.


Static
Rising
Static
Plant is leeching nutrition, raise EC. Note 2


Static
Rising
Rising
Plant leeching nutrition, Raise EC. An unusual state. The rising ph is probably caused by what nutrient leeching back.
If these are alkaline, it will lead to the rise in ph. Could also be ph buffers.


Static
Rising
Falling
As above but be aware of the acid rain effect mentioned in note 1. Res change, plus increase in EC.


Static
Falling
Static
Plant eating but not drinking. Not ideal. Lower EC or res change.


Static
Falling
Rising
As above but rising ph is a better sign. Lower EC slightly or res change


Static
Falling
Falling
Falling ph along with falling EC but no drop in water level suggests a res change. Could also be an acid rain effect as per note 1. Depending on other symptoms, lowering EC after res change.


Falling
Static
Static
Perfect conditions. EC and ph are at the correct level.


Falling
Static
Rising
Normal state most people encounter. Nothing to worry about, carry on doing what you are doing unless other plant symptoms.


Falling
Static
Falling
Res change plus a change of EC. Lower EC if over 1.4, raise EC if lower than 1.0


Falling
Rising
Static
Plant is drinking more than eating, lower EC.


Falling
Rising
Rising
Plant is drinking more than eating, lower EC.


Falling
Rising
Falling
Plant is drinking more than eating, lower EC. Also, res change due to possible acid rain problem.


Falling
Falling
Static
Hungry plant, raise EC. Very good situation to be in. Nute buffers are working and plant is taking a balance of nutrients.


Falling
Falling
Rising
Almost as above, usually considered almost perfect, raise EC slightly.


Falling
Falling
Falling
Res change. Potential acid rain issue but plant is still eating & drinking. Raise EC on new res.


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. Even a moderate plant that will be yielding 3 or 4 oz should be going through 3 or 4 l of water per day. I have seen me giving larger plants as much as 10l per day food & water, its like keeping a horse! But you cant smoke a horse.


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 lower 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!

[DaveB22]

Though it may be like reading the small print of a contract, here is a downloadable single page pdf version of that table you can print out and hang on the wall.

411974

[Delahaze]

Very helpful woody, thank you