Help with difference in ec

[AnnFrank]

Hi, I swapped my feeding schedule over today, I filled the my main (120L) feed tank with 90l of water the ec of the tap water was 0.4 I added the nutes as recommended by the canna guid, the ec of the tank read at 2.2 after filling

I’d let my pots run nearly dry over the last week there was only about a inch in the bottom,

I’ve got 8 plants and a header tank all the same size 20L pots

after opening the tap from the main 120L tank and letting the system fill about half way I checked the ec and it was up around 7

I got nervous and turned the tap off and filled the system with clean water to try dilute it a bit which has brought it down to 4 ish

I don’t suppose anyone might no the reason for this massive spike in difference

thanks

 

[amneziaHaze]

If its a dwc grow plants probably drank only water because nutes was too strong.more they drink higher the ec went.if its not dwc maybe you got a bad instrument

 

[Drop That Sound]

I notice the temp is different, which could have an impact on the readings. Some meters are finicky about that, or take longer with colder water, etc. I dunno about off the chart readings like that though, unless the meter is going out of whack or something.. Maybe you added double the amount of something. It happens

Check the batteries to start with. Test with different jars of plain tap water at different temps to see if it skews the readings like in the pics. CAL it with the proper solution. Are you sure everything is mixed up well, and you waited long enough for the pump to cycle all of the solution before testing? It could take quite awhile. 7 is really high though.. was that the 2 inches that was left you tested? Is the 4.8 because you topped off with the new 2.3 solution, and it mixed with the old 2 inches that was already high EC or something?

 

[TCH]

What are the details of the grow? Rdwc? Media? Etc...

In any hydro application though, I think drying out is not a great move and can cause issues.

 

[AnnFrank]

I notice the temp is different, which could have an impact on the readings. Some meters are finicky about that, or take longer with colder water, etc. I dunno about off the chart readings like that though, unless the meter is going out of whack or something.. Maybe you added double the amount of something. It happens

Check the batteries to start with. Test with different jars of plain tap water at different temps to see if it skews the readings like in the pics. CAL it with the proper solution. Are you sure everything is mixed up well, and you waited long enough for the pump to cycle all of the solution before testing? It could take quite awhile. 7 is really high though.. was that the 2 inches that was left you tested? Is the 4.8 because you topped off with the new 2.3 solution, and it mixed with the old 2 inches that was already high EC or something?

there was about 2 inches left across the 9 pots / system I did not check the ec of the water that was in it but it was around 2 last time I checked it a few days ago,

I tested the the pots after I added about 40L to the system, which filled the pots about half -2/3rds, when I checked the reading to see it was up around 7 panicked and filled the pots with tap water to try and dilute it, the photo in the pot at 4+ is the last reading I took of the ec in the system after all this has been done, which in my eyes is still way to high

 

[AnnFrank]

What are the details of the grow? Rdwc? Media? Etc...

In any hydro application though, I think drying out is not a great move and can cause issues.

its rdwc and the root system have been in enough water to be keeping them selfs healthy. All plants are praying

 

[AnnFrank]

If its a dwc grow plants probably drank only water because nutes was too strong.more than drink higher the ec went.if its not dwc maybw you got a bad insteument

never thought about that, I didn’t check the ec of the water before I filled the system

 

[amneziaHaze]

never thought about that, I didn’t check the ec of the water before I filled the system

best way for me in dwc is i see the nutes ppm or ec and then check it tommorow it will go up or down then you know if they are eating too little or too much.and if it doesnt move then you are perfect.
problem is when you have more than one plant in the same water then one can eat more other less but you get the average of both.its harder to figure out their needs

 

[AnnFrank]

best way for me in dwc is i see the nutes ppm or ec and then check it tommorow it will go up or down then you know if they are eating too little or too much.and if it doesnt move then you are perfect.
problem is when you have more than one plant in the same water then one can eat more other less but you get the average of both.its harder to figure out their needs, all the other plants are allot bigger and same for the root stock

yeh it’s been a bit of a pain, 2 of the plants were stunted after I accidentally burnt them after transplanting them in the same sort of way with the ec and haven’t really grown, they have always shown a cal/mag issue I’ve tried to figure out if it was to much or to less but when all the others have just been loving what they have been fed on I figured they can suffer in silence as it’s pointless stressing the other 6 for the sake of 2 small plants, if I put them in clean water they showed signs if I put them with more cal mag they showed signs, I just figured they were being awkward so can’t wait to get them out the way

 

[AnnFrank]

Did some digging about, took some water out and replaced with clean got the ec down to
About 2.2 so gonna leave it a bit to mix properly, noticed the head on the pump wasn’t what it should be so checked the filter, the return (20mm) line was just as bad and blocked with gunk, I’ve never seen the filter so bad after so short a time

 

[Mumbeltypeg]

Yeah perhaps you should try running at a lower ec.. say 1.6.. the idea is to get the plants drinking the water and nutes at the same rate.. if it’s going up to 7 as the tank gets lower your mix is too strong for optimal uptake.

Also pull one of your plant up and take a photo of the roots, you may have a pithium problem if your lines are getting slimy.. I imagine your ph is probably swinging also?

 

[AnnFrank]

Yeah perhaps you should try running at a lower ec.. say 1.6.. the idea is to get the plants drinking the water and nutes at the same rate.. if it’s going up to 7 as the tank gets lower your mix is too strong for optimal uptake.

Also pull one of your plant up and take a photo of the roots, you may have a pithium problem if your lines are getting slimy.. I imagine your ph is probably swinging also?

this is the smallist plant that’s struggling



this is one of the bigger plants that’s doing better

and I’ve been using this stuff to keep the system “clean” reading the back of the bottle and it sais every 7 days, I’ve only been adding it with the feed

 

[Mumbeltypeg]

this is the smallist plant that’s struggling

View attachment 5370863View attachment 5370864

this is one of the bigger plants that’s doing better View attachment 5370867View attachment 5370865

and I’ve been using this stuff to keep the system “clean” reading the back of the bottle and it sais every 7 days, I’ve only been adding it with the feed View attachment 5370868

Those roots look fine.. the little one definitely looks a bit poorly.. perhaps that big split on the branch let some pathogens in? Just guessing tho. Nice looking set up. Stocky little plants too. Have you got your vpd dialled in?

 

[AnnFrank]

Those roots look fine.. the little one definitely looks a bit poorly.. perhaps that big split on the branch let some pathogens in? Just guessing tho. Nice looking set up. Stocky little plants too. Have you got your vpd dialled in?

most big cuts and snaps I seal with pva to stop any open wounds, and yeh I got it wrong from the start, I had it dialled for about 300 but a friend had turned them up and down but not all the way back down, I’m not sure why it took so long to realise, I was raising the light 2 clicks on the yo-yos every day but now doing it by 4 plus turning the lights down got them to finally start stretching, but by then they had just grown pretty short and dumpy, I’m hoping that they come out nice tho, took a bunch of cuttings to try again next run and see if i can get a better canopy, checked the ppfd it’s about 6 I’ve also got the ec down to 1.8 and ph at 6 but even just yesterdays balls up plants are starting to show signs of burn so I’m a little annoyed at my self, but lessons learnt … it’s what it’s all about

 

[Hollatchaboy]

If you're doing rdwc, get one of these....



You can leave the probes in the control bucket, that way you can monitor real time, what's going thru the system.

 

[AnnFrank]

If you're doing rdwc, get one of these....

View attachment 5371017

You can leave the probes in the control bucket, that way you can monitor real time, what's going thru the system.

I did get a cheap version of something like that of Alibaba kinda wished I’d saved my money, readings are a million miles out even on temp so ended up unplugging it, but i will definitely get one as soon as i can get some money saved

 

[Hollatchaboy]

I did get a cheap version of something like that of Alibaba kinda wished I’d saved my money, readings are a million miles out even on temp so ended up unplugging it, but i will definitely get one as soon as i can get some money saved View attachment 5371031

Yea, I used one of those back in 2011. Those cheap ones kinda suck, mostly just the ph sensor though.


The bluelab is quality and if you keep up with the maintenance, it'll last quite a while.

 

[Drop That Sound]

I agree with lowering the EC.

Around 1.0 for veg is more like it IMO, or a little bit higher with your unfiltered .4 tap water adding to the total..

2.0+ is pushing it with DWC, even in peak of flower. 1.8 is around the max I've ever seen hungry strains uptake when dialed in with any of my setups (w/o c02), where they are eating and drinking the solution/feed at the same rate. Never mind what any nutrient feed schedules say.. Its better to monitor the res daily and adjust in smaller increments as necessary over time, depending on what they ask for.

Hard to tell because of the risers in the lids, but you are keeping the water level just under the bottom of the net pots, right? Not above it?.. When you're not letting the system become depleted that is? Drying out bare roots def isn't good, and it can take weeks to repair such an event, especially if the EC/PH of the solution rapidly swings one way or another or becomes more concentrated as the level drops. Even if the roots don't technically dry out with some water still in the bottom, the air stones basically bubble and mist the roots like an aero system, with whatever acidic solution is still left. Not good.. You don't want drastic fluctuations like that, and need to keep the solution more stable.

I would suggest installing a top off system/valve/kit, that continuously adds back solution and keeps the water level in check, once you get a better idea of exactly how much to feed, by monitoring the levels closely for awhile. Until you find the sweet spot, where they eat and drink the same rate like mumblety says. then you can get an idea on the correct solution to top back off with, which could just be plain water unless you wanna get fancy. You could even add the root rot x solution to the top off res, so it continuously administers a lower concentration as it adds back the extra solution throughout the week. Lots of ways to go about it, but yeah Its a good safegaurd against letting them dry out ever again,as long as you make it flood proof with decent valves that won't get caught up or leak when your not around..

 

[AnnFrank]

I agree with lowering the EC.

Around 1.0 for veg is more like it IMO, or a little bit higher with your unfiltered .4 tap water adding to the total..

2.0+ is pushing it with DWC, even in peak of flower. 1.8 is around the max I've ever seen hungry strains uptake when dialed in with any of my setups (w/o c02), where they are eating and drinking the solution/feed at the same rate. Never mind what any nutrient feed schedules say.. Its better to monitor the res daily and adjust in smaller increments as necessary over time, depending on what they ask for.

Hard to tell because of the risers in the lids, but you are keeping the water level just under the bottom of the net pots, right? Not above it?.. When you're not letting the system become depleted that is? Drying out bare roots def isn't good, and it can take weeks to repair such an event, especially if the EC/PH of the solution rapidly swings one way or another or becomes more concentrated as the level drops. Even if the roots don't technically dry out with some water still in the bottom, the air stones basically bubble and mist the roots like an aero system, with whatever acidic solution is still left. Not good.. You don't want drastic fluctuations like that, and need to keep the solution more stable.

I would suggest installing a top off system/valve/kit, that continuously adds back solution and keeps the water level in check, once you get a better idea of exactly how much to feed, by monitoring the levels closely for awhile. Until you find the sweet spot, where they eat and drink the same rate like mumblety says. then you can get an idea on the correct solution to top back off with, which could just be plain water unless you wanna get fancy. You could even add the root rot x solution to the top off res, so it continuously administers a lower concentration as it adds back the extra solution throughout the week. Lots of ways to go about it, but yeah Its a good safegaurd against letting them dry out ever again,as long as you make it flood proof with decent valves that won't get caught up or leak when your not around..

there’s a header tank with a float in, so it’s only as full as it should be, it’s all fed from a 120L tank outside the tent, the tank was emptied and I’d only let the pots drain down so it was easer to measure the the 100L going into the system for the switch, but yeh maybe should have measured it out and just let it keep the system topped up, every days a school day

 

[Mumbeltypeg]

most big cuts and snaps I seal with pva to stop any open wounds, and yeh I got it wrong from the start, I had it dialled for about 300 but a friend had turned them up and down but not all the way back down, I’m not sure why it took so long to realise, I was raising the light 2 clicks on the yo-yos every day but now doing it by 4 plus turning the lights down got them to finally start stretching, but by then they had just grown pretty short and dumpy, I’m hoping that they come out nice tho, took a bunch of cuttings to try again next run and see if i can get a better canopy, checked the ppfd it’s about 6 I’ve also got the ec down to 1.8 and ph at 6 but even just yesterdays balls up plants are starting to show signs of burn so I’m a little annoyed at my self, but lessons learnt … it’s what it’s all about View attachment 5370994

That’s your PPFD, and good your keeping an eye on that.. VPD is your vapour pressure deficit.. basically the magic number when you get your room Temp/Humidity/leaf surface temps just right.. and when you do you get better growth as you plants transpire at the right rate and draw up nutrients and water better and are just all round happier plants.
Just look up VPD charts for an idea of what balance you want for your setup.