Questions about EC levels in hydro, interpreting EC rise, and native EC from tap

G

Greenhorn_Greenthumb

Member
So I’ve got an approx 25-30gal RDWC that houses up to 4 plants and I’ve never once seen my EC levels go down over time no matter how little I feed and what I set them at. 4 weeks into flowering and I can barely feed at 1.0 EC (500 ppm) and it will end up holding steady as water levels go down. If I up the EC to something like 1.3 (650 ppm) I start to see a slow rise, but really slow like +10 ppm a day)

my first question is with a total volume of nearly 30gals I know the effect of rising and lowering EC will be less noticeable but should I really be reacting to a rise of +10 ppm a day and lowering its feed levels because of that, or is a rise of that little somewhat expected and no big deal? Keeping in mind that we’re talking about a 30gal reservoir being moved here by maybe just 2 plants.

next question is about the native ppm of my tap water. I’m filtering out any chlorine or chloramine but still using tap that has a native ppm of around 110 ppm. That 110 native ppm is a factor in all those figures above so when I say I can feed at a 1.0 EC and still never see EC levels drop that’s actually .2 EC (110 ppm) from tap water and only .8 EC of nutrients and at best my EC levels will stay consistent but still never drop. But my big question here about that 110 ppm tap is CalMag levels from a feed chart. I’m using GH flora series and it is based off of using RO, I’ve been cutting the CalMag levels by 50% from what it calls for since I’m using tap, but with 110ppm coming from the tap should I just cut out the CalMag completely? Are odds pretty good that the plants will get all the CalMag they need from 110ppm tap, or do you think I should stick to a 50% ratio of the feed chart?
 
Milky Weed

Milky Weed

Well-Known Member
Greenhorn_Greenthumb said:
So I’ve got an approx 25-30gal RDWC that houses up to 4 plants and I’ve never once seen my EC levels go down over time no matter how little I feed and what I set them at. 4 weeks into flowering and I can barely feed at 1.0 EC (500 ppm) and it will end up holding steady as water levels go down. If I up the EC to something like 1.3 (650 ppm) I start to see a slow rise, but really slow like +10 ppm a day)

my first question is with a total volume of nearly 30gals I know the effect of rising and lowering EC will be less noticeable but should I really be reacting to a rise of +10 ppm a day and lowering its feed levels because of that, or is a rise of that little somewhat expected and no big deal? Keeping in mind that we’re talking about a 30gal reservoir being moved here by maybe just 2 plants.

next question is about the native ppm of my tap water. I’m filtering out any chlorine or chloramine but still using tap that has a native ppm of around 110 ppm. That 110 native ppm is a factor in all those figures above so when I say I can feed at a 1.0 EC and still never see EC levels drop that’s actually .2 EC (110 ppm) from tap water and only .8 EC of nutrients and at best my EC levels will stay consistent but still never drop. But my big question here about that 110 ppm tap is CalMag levels from a feed chart. I’m using GH flora series and it is based off of using RO, I’ve been cutting the CalMag levels by 50% from what it calls for since I’m using tap, but with 110ppm coming from the tap should I just cut out the CalMag completely? Are odds pretty good that the plants will get all the CalMag they need from 110ppm tap, or do you think I should stick to a 50% ratio of the feed chart?
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Do not cut the calmag, that’s not quite enough ppm in your source water. Do not worry about pushing high EC, if the plants are healthy follow course.
 
G

Greenhorn_Greenthumb

Member
Milky Weed said:
Do not cut the calmag, that’s not quite enough ppm in your source water.
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do not cut it out completely or do not cut it by 50% like I’ve already been doing?
I thought that the 50% cut might have been a good compromise from RO water + feed chart amounts to compensate for there being at least something in that 110ppm tap water
 
rkymtnman

rkymtnman

Well-Known Member
my well water is .2EC and i've only had 1 strain have a Ca issue. i normally just use epsom salt for the Mg.

do you get Ca issues if you don't use the Cal/Mg?
 
G

Greenhorn_Greenthumb

Member
rkymtnman said:
do you get Ca issues if you don't use the Cal/Mg?
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haven’t tried without it yet but that’s where my head is going….
previous runs as I’ve been getting my feet wet with all of this I’ve been mistakingly chasing high EC levels and haven’t given the plants their ideal living situations and now I’m realizing this. I’ve also questioned tastes and flavors in the outcomes that haven’t been ideal and hit my palette pleasantly.

thats exactly why this run I’ve been trying to test the lower limits of my EC levels and have been hoping to find and observe a dropping EC level to see it happen with my own eyes and work it from there so I can test it’s effect on my tastes and flavors at the end. Rather than overfeed I wanted to come real close to underfeeding this one
 
G

Greenhorn_Greenthumb

Member
rkymtnman said:
and i run my dwc with 0.2EC well water and 0.5 to 0.6EC nutes for 0.7 to 0.8 total.
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im on my like 5th run and am just now grasping that these seem to be around what I should be aiming for, and not the 1.8-2.0 (and up) EC level claims that are lingering around out there in Internet threads and comments. those plants have to be getting burned
 
Milky Weed

Milky Weed

Well-Known Member
Greenhorn_Greenthumb said:
im on my like 5th run and am just now grasping that these seem to be around what I should be aiming for, and not the 1.8-2.0 (and up) EC level claims that are lingering around out there in Internet threads and comments. those plants have to be getting burned
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Personally I may not know shit because I’m a new grower, but it seems like there are critical points in flower where you can up the EC a good bit then lower it back down without too many bad effects. This run I’m going the mininal route also, seeing the bare minimum it needs for healthy growth.
 
Billy the Mountain

Billy the Mountain

Well-Known Member
Seems the high-EC bandwagon is largely new nute lines and youtube shills.

I rarely exceeded 1.2 EC in DWC, currently just a bit higher in coco without any signs of deficiencies.
 
rkymtnman

rkymtnman

Well-Known Member
Greenhorn_Greenthumb said:
im on my like 5th run and am just now grasping that these seem to be around what I should be aiming for, and not the 1.8-2.0 (and up) EC level claims that are lingering around out there in Internet threads and comments. those plants have to be getting burned
Click to expand...
there are alot of reason for needing a lower EC:
i'm at high altitude 9000ft
low light levels
low RH%
low feeding strains
etc.

feed your plants what they need, not based on labels or instructions or what your buddy runs at
 
G

Greenhorn_Greenthumb

Member
rkymtnman said:
there are alot of reason for needing a lower EC:
i'm at high altitude 9000ft
low light levels
low RH%
low feeding strains
etc.
Click to expand...
high DO levels will prompt lower desired EC levels too won’t it? I think I’ve picked that up recently.
and my set-up is modeled after the Medgrower1 rdwc from YouTube with the waterfalls into the buckets (adds DO) running from a Danner with a Venturi intake (adding DO) over top of 5” air stones (adding DO)

my current EC levels on this run are a world away from where they were on my first run
 
Star Dog

Star Dog

Well-Known Member
Milky Weed said:
Personally I may not know shit because I’m a new grower, but it seems like there are critical points in flower where you can up the EC a good bit then lower it back down without too many bad effects. This run I’m going the mininal route also, seeing the bare minimum it needs for healthy growth.
Click to expand...
That's correct ime, weeks 3-5 can eat through a lot of ec with ideal conditions and lighting.
I used 1.2ec with my 600w hps for ever but when I swapped to 720w led I couldn't keep up with the ec through weeks 3-5, I was getting consistently low run off so I increased the ec gradually I was up to 2.0 before the run off raised above 0.9ec and leveled out.
I believe that was critical time wasted... I'll catch it right next time :-)
 
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