EC drops a lot in runoff

[phxazcraig]

I'm 6 weeks into my first coco coir grow, four plants in a 4x4 tent. For the past couple of weeks I've been watering 4x a day with 10-20% runoff. I'm not entirely sure the amount I'm pumping 30 seconds at a time through 6-inch rings), but I think about 3/4 of a liter (per pot). pH controlled at 6.0 by a bluelab controller. 3.5 gallon air pots. Coco coir/pearlite mix. Plants are looking great and growing very rapidly. Silicone, Calmag, GH nutes, Humic Acid and some Yucca powder in RO water. The calmag was about .5 of the EC, the rest from nute

Here is the question: Is it concerning that my EC is dropping from 1.800 input to 1.050 runoff in a DTW system? Is it just that the plants are using up the nutrients that quickly?

 

[PK1]

Here is the question: Is it concerning that my EC is dropping from 1.800 input to 1.050 runoff in a DTW system? Is it just that the plants are using up the nutrients that quickly?

that, and coco absorbs a lot of Mg

 

[2Bad]

Any Algae yet? as long as they are healthy I would say you're good but when you get algae get some enzymes to control it @Aqua Man recommended them to me I ended up getting pond enzymes cus they are cheaper.

 

[phxazcraig]

Any Algae yet? as long as they are healthy I would say you're good but when you get algae get some enzymes to control it @Aqua Man recommended them to me I ended up getting pond enzymes cus they are cheaper.

No algae now. There was a hunt earlier, but after spraying with Neem oil and some h2o2, all gone. That was before the canopy got so thick as to shade the pots a lot. Now I add h2o2 to the reservoir and algae is gone there and in the drains.

 

[phxazcraig]

It's been a good week where my runoff EC is significantly lower than input EC. At the beginning of the week I was seeing 600-800 point drops in EC, now I'm at 400, maybe 300 less than input. The plants seem fine.

Is this normal?

I've been growing mostly according to cocoforcannabis.com tutorials, and things are working better than I've ever seen before, but those tutorials also think runoff EC should be higher than input, by as much as 300 points. I do water 4x/day with 10%+ runoff. Plants are in 3.5 gallon airpots. Input EC this week is 1580, output is around 1280.

 

[phxazcraig]

I'm 6 weeks into my first coco coir grow, four plants in a 4x4 tent. For the past couple of weeks I've been watering 4x a day with 10-20% runoff. I'm not entirely sure the amount I'm pumping 30 seconds at a time through 6-inch rings), but I think about 3/4 of a liter (per pot). pH controlled at 6.0 by a bluelab controller. 3.5 gallon air pots. Coco coir/pearlite mix. Plants are looking great and growing very rapidly. Silicone, Calmag, GH nutes, Humic Acid and some Yucca powder in RO water. The calmag was about .5 of the EC, the rest from nute

Here is the question: Is it concerning that my EC is dropping from 1.800 input to 1.050 runoff in a DTW system? Is it just that the plants are using up the nutrients that quickly?

It's been a while since I asked about this, but I'm still not understanding what is going on with my grow. I figure it must be ok, because the plants look great, but I then wonder why so I read that EC should be rising up to 300 EC in the runoff. Mine is still coming out less than the input, though the gap has reduced to about 100 EC in the latest watering.

 

[2Bad]

It's been a while since I asked about this, but I'm still not understanding what is going on with my grow. I figure it must be ok, because the plants look great, but I then wonder why so I read that EC should be rising up to 300 EC in the runoff. Mine is still coming out less than the input, though the gap has reduced to about 100 EC in the latest watering.

@Moe.Red i'm having a stoner moment I can't remember any coco members right now lmao I just know that higher EC is a problem but only if its way off. and im not sure but I think lower ec means its effectively using the nutirents

 

[Brettdawg]

Lower ec run off means can bump or feed abit more.

 

[phxazcraig]

My runoff EC has been rising since about the time I turned the lights from 18/6 to 12/12. Also some defoliation, and definitely the plants have filled the tent now.

For the first time, my runoff ec was a bit higher than input today, by 100 points. About 1650 out, 1550 in.

 

[Brettdawg]

Thats not to bad bro. Chek out the chart below

 

[jguit]

That more or less agrees with what the folks at JR Peter's (Jacks) recommend as well.

Getting Technical - Fertigation and Continuous Liquid Feeding

How many times a day (week, month) should I be feeding my plants with Jack's Nutrients? That's a great question, and while ultimately, the answer varies between grows, this week we give you the information to determine what works for the setup you have in place. This week's Getting Technical...

www.jacksnutrients.com

 

[phxazcraig]

My runoff EC has completely reversed itself over the past 2.5 weeks, since I flipped to 12/12 lighting, and did a fair amount of defoliation.

Early in the grow, my runoff EC was up to 800 points lower than input. That gradually changed until it was maybe 300 points lower about the time I went to flower. Immediately my runoff EC began to go upward, peaking yesterday at 2000 out, 1400 in. I don't know what's going on, but I am seeing a bit of tip burn on some shoots. I've lowered input EC to 1200, and this morning runoff down to 1800.

Something's changed. I bought some FloraKleen to try a flush. 5x/day fertigation with runoff.

 

[jguit]

I've experienced more or less the same of what you are seeing. Anything over 1 or so EC in runoff and i began to see slight slight tip burn. Below 1 things seem to be ok but imagine this would be strain dependent. I try to keep runoff in the .4 ish EC range. No need to use a flush product. Just run a bunch of feed at the desired EC until your runoff is close to the input.

You can balance things out by lowering your EC, increasing fertigation frequency, increase the amount of runoff or all of the above.

I'm just starting week 7 of flower, fertigating 1 Gal fabric pots 11 times a day @ 1.4 EC and this keeps my runoff about .4 EC above input with no issues.

 

[phxazcraig]

I've experienced more or less the same of what you are seeing. Anything over 1 or so EC in runoff and i began to see slight slight tip burn. Below 1 things seem to be ok but imagine this would be strain dependent. I try to keep runoff in the .4 ish EC range. No need to use a flush product. Just run a bunch of feed at the desired EC until your runoff is close to the input.

You can balance things out by lowering your EC, increasing fertigation frequency, increase the amount of runoff or all of the above.

I'm just starting week 7 of flower, fertigating 1 Gal fabric pots 11 times a day @ 1.4 EC and this keeps my runoff about .4 EC above input with no issues.

I guess I'm heading there too - more feedings. What I don't know, and it bothers me I don't know, is why the EC level has changed so dramatically.

I'm ok with extra watering, but it does make a strain on my ability to keep the reservoir filled. Used to fill 2x a week, and it's heading toward ever 2 days. I have a 14 gallon reservoir, and a 10-11 gallon mixing tank. (Mix tank is a plastic tub I set up on bathroom counter to mix into. Then I siphon into buckets and carry next room to pour into reservoir.)

I'm inclined to fill a watering can with fresh RO water and just hand water each plant to get a gallon of runoff, and see how that goes.

By the way, I belatedly realized I'd not been measuring the runoff correctly, though the numbers are close. I was measuring what was pumped out of the sump bucket, after all the pots drained into it. That mixes 4 plants together, and it hides any that are off a lot from the others. Also, there is a 1 inch stand of water left in the (small) bucket that is further averaging out the results.

I've started trying to pull samples from each drain saucer using a turkey baster to get the runoff right as it comes out of the coco. Pain, but works. And indicates EC above 2000 yesterday, though the 'drain average' is down to 1800 today, after I diluted input down to 1200 EC last night.

I'll add a 6th feeding to the schedule. And order more nutes...

 

[jguit]

5 gal fabric pots

I guess I'm heading there too - more feedings. What I don't know, and it bothers me I don't know, is why the EC level has changed so dramatically.

My guess is nutritional changes and that the media is drying back more than you think, leading to salt buildup/increased EC.

I'm ok with extra watering, but it does make a strain on my ability to keep the reservoir filled. Used to fill 2x a week, and it's heading toward ever 2 days. I have a 14 gallon reservoir, and a 10-11 gallon mixing tank. (Mix tank is a plastic tub I set up on bathroom counter to mix into. Then I siphon into buckets and carry next room to pour into reservoir.)

Reservoir size is certainly one thing i'm going to address on my next grow. Maybe consider using a transfer pump so that you dont have to carry all that water. Right now i'm using 5 gallon buckets to transfer liquid as well. Luckily I don't have to carry the buckets very far.

I'm inclined to fill a watering can with fresh RO water and just hand water each plant to get a gallon of runoff, and see how that goes.

It's my understanding that it's never a good idea to flush with plain RO water. If anything, just use a lower EC (pH'd) feed. That said, if you run about 2-3 times your container size of liquid through your coco at the desired EC, rest assured, your EC will match your input and you'll know you have the proper nutrient ratios in your media.

By the way, I belatedly realized I'd not been measuring the runoff correctly, though the numbers are close. I was measuring what was pumped out of the sump bucket, after all the pots drained into it. That mixes 4 plants together, and it hides any that are off a lot from the others. Also, there is a 1 inch stand of water left in the (small) bucket that is further averaging out the results.

I've started trying to pull samples from each drain saucer using a turkey baster to get the runoff right as it comes out of the coco. Pain, but works. And indicates EC above 2000 yesterday, though the 'drain average' is down to 1800 today, after I diluted input down to 1200 EC last night.

I do something similar, I use a 10ml pipette to grab a few samples of run-off before it goes down the drain into my pump. You do get an average of all your pots
but i think that's enough to know if you're heading in the wrong direction. Fresh run-off gathers at my drain before the pump, so this is fairly easy.

 

[phxazcraig]

My guess is nutritional changes and that the media is drying back more than you think, leading to salt buildup/increased EC.

Reservoir size is certainly one thing i'm going to address on my next grow. Maybe consider using a transfer pump so that you dont have to carry all that water. Right now i'm using 5 gallon buckets to transfer liquid as well. Luckily I don't have to carry the buckets very far.

It's my understanding that it's never a good idea to flush with plain RO water. If anything, just use a lower EC (pH'd) feed. That said, if you run about 2-3 times your container size of liquid through your coco at the desired EC, rest assured, your EC will match your input and you'll know you have the proper nutrient ratios in your media.

I do something similar, I use a 10ml pipette to grab a few samples of run-off before it goes down the drain into my pump. You do get an average of all your pots
but i think that's enough to know if you're heading in the wrong direction. Fresh run-off gathers at my drain before the pump, so this is fairly easy.

My guess is nutritional changes and that the media is drying back more than you think, leading to salt buildup/increased EC.

Reservoir size is certainly one thing i'm going to address on my next grow. Maybe consider using a transfer pump so that you dont have to carry all that water. Right now i'm using 5 gallon buckets to transfer liquid as well. Luckily I don't have to carry the buckets very far.

It's my understanding that it's never a good idea to flush with plain RO water. If anything, just use a lower EC (pH'd) feed. That said, if you run about 2-3 times your container size of liquid through your coco at the desired EC, rest assured, your EC will match your input and you'll know you have the proper nutrient ratios in your media.

I do something similar, I use a 10ml pipette to grab a few samples of run-off before it goes down the drain into my pump. You do get an average of all your pots
but i think that's enough to know if you're heading in the wrong direction. Fresh run-off gathers at my drain before the pump, so this is fairly easy.

My guess is nutritional changes and that the media is drying back more than you think, leading to salt buildup/increased EC.

As long as it's not some sort of rot or pest.

Reservoir size is certainly one thing i'm going to address on my next grow. Maybe consider using a transfer pump so that you dont have to carry all that water. Right now i'm using 5 gallon buckets to transfer liquid as well. Luckily I don't have to carry the buckets very far.

I don't mind carrying bucje6s. Good exercise. But I only want to do it once a week.

It's my understanding that it's never a good idea to flush with plain RO water. If anything, just use a lower EC (pH'd) feed. That said, if you run about 2-3 times your container size of liquid through your coco at the desired EC, rest assured, your EC will match your input and you'll know you have the proper nutrient ratios in your media.

I'm thinking here about diluting current mix by half, but then running the while reservoir in a couple of feedings over 3 hours.

I do something similar, I use a 10ml pipette to grab a few samples of run-off before it goes down the drain into my pump. You do get an average of all your pots
but i think that's enough to know if you're heading in the wrong direction. Fresh run-off gathers at my drain before the pump, so this is fairly easy.

Still working on a better process. Really, I'm not sure I need to sample each pot, but I have to first test to know. The new grow tent is inconvenient to enter, and I'd prefer catching the runoff out of the sump.

 

[dbrzz]

I'm 6 weeks into my first coco coir grow, four plants in a 4x4 tent. For the past couple of weeks I've been watering 4x a day with 10-20% runoff. I'm not entirely sure the amount I'm pumping 30 seconds at a time through 6-inch rings), but I think about 3/4 of a liter (per pot). pH controlled at 6.0 by a bluelab controller. 3.5 gallon air pots. Coco coir/pearlite mix. Plants are looking great and growing very rapidly. Silicone, Calmag, GH nutes, Humic Acid and some Yucca powder in RO water. The calmag was about .5 of the EC, the rest from nute

Here is the question: Is it concerning that my EC is dropping from 1.800 input to 1.050 runoff in a DTW system? Is it just that the plants are using up the nutrients that quickly?

If you are running a recirculating DWC system, The drop in EC indicates the plant is consuming The nutrients faster than the water supplied. You mentioned you had a bluelab controller, is this a fertigation dosing system controller that adjusts your nutrient strength up or down? If this is the case then I would simply increase my nutrient strength so my runoff matches my input then you have balance usage of your nutrient solution strength by your plant. When I used a recirculating system when my nutrient solution start tank say 5 gallons starts reducing in the reservoir by plant consumption of the solution, I would simply top up my reservoir with RO water pH @6.0 And continue adding just water daily until I’ve added 5 gallons. At that point it’s time to change nutrient solution for a new batch. If you use a recirculating system and you keep adding to your reservoir the same strength solution as your start strength you can get problems with nutrient increases and lockouts. This is been my experience. Good luck

 

[dbrzz]

If you are running a recirculating DWC system, The drop in EC indicates the plant is consuming The nutrients faster than the water supplied. You mentioned you had a bluelab controller, is this a fertigation dosing system controller that adjusts your nutrient strength up or down? If this is the case then I would simply increase my nutrient strength so my runoff matches my input then you have balance usage of your nutrient solution strength by your plant. When I used a recirculating system when my nutrient solution start tank say 5 gallons starts reducing in the reservoir by plant consumption of the solution, I would simply top up my reservoir with RO water pH @6.0 And continue adding just water daily until I’ve added 5 gallons. At that point it’s time to change nutrient solution for a new batch. If you use a recirculating system and you keep adding to your reservoir the same strength solution as your start strength you can get problems with nutrient increases and lockouts. This is been my experience. Good luck

And DTW system in Coco coir, is what I’m growing in right now and it’s the same principal. Water till you get 10 to 20% runoff the runoff pH and EC will indicate the consumption of the nutrients. If the pH rises and the nutrient EC does not then you may need to add a little more nutrient. On the other hand if your runoff pH is dropping, your EC is probably rising compared to your starting solution and this is indicative of your solution strength being too high. So probably too much nutrient. I try for around 1.1-1.5 EC most cannabis plant types like this feed strength.

 

[tuanha]

I'm 6 weeks into my first coco coir grow, four plants in a 4x4 tent. For the past couple of weeks I've been watering 4x a day with 10-20% runoff. I'm not entirely sure the amount I'm pumping 30 seconds at a time through 6-inch rings), but I think about 3/4 of a liter (per pot). pH controlled at 6.0 by a bluelab controller. 3.5 gallon air pots. Coco coir/pearlite mix. Plants are looking great and growing very rapidly. Silicone, Calmag, GH nutes, Humic Acid and some Yucca powder in RO water. The calmag was about .5 of the EC, the rest from nute

Here is the question: Is it concerning that my EC is dropping from 1.800 input to 1.050 runoff in a DTW system? Is it just that the plants are using up the nutrients that quickly?

i think your plan so hungry you need to put more ec for nutrients

 

[phxazcraig]

Runoff EC has risen the last 5 feedings in a row. I'm at 1200 in, 1650 out last time. And I'm well over 20% run off. I get 4 gallons a day in my runoff bucket, and about 5 or 6 out of the reservoir. The extra water was an attempt to get EC down. Clearly that's not worked, nor dropping the input EC. So...I'll try more, shorter watering. And keep EC down.

I feel lucky so far on this grow. Like everything's gone right - my biggest problem has been plants growing too big. I keep waiting for something to go wrong in the last month.