What's new
  • As of today ICMag has his own Discord server. In this Discord server you can chat, talk with eachother, listen to music, share stories and pictures...and much more. Join now and let's grow together! Join ICMag Discord here! More details in this thread here: here.

High runoff during flush in Coco

Caperoots

New member
Any suggestions as to why my runoff is coming out so high after a week of PH’d water flush? Was almost 2000ppm when my feeds were 1200ppm at most.
 

Creeperpark

Well-known member
Mentor
Veteran
If you are using Tap water to flush, you will leave a build up of neg anions in the substrate every time you flush. When the anions are present, they block exchange sites and won't release the cations from the substrate. For the best flush use a RO or rain water with a very low ppm of nutrient in it. 😎
 

f-e

Well-known member
Mentor
Veteran
We can't measure PPM. It's invented, with no single fixed method. The number is meaningless without context. Is it high? I don't think it is.

You don't flush CoCo unless you want to buffer it again, which takes days. K and Sodium will take over.

I can water 4 times a day and see 90ppm K from the coco. That's a real 90ppm from water analysis. CoCo breaks down, releasing it. It's not from your feed.

It releases a lot of K and Sodium. Leaving cation exchange sites. If you have empty sites, any free cation can attach. If all you have is the K and Sodium, then they will cover the CoCo. You should always make sure lots of free Ca and Mg are present, in order to get a good share of them coating the CoCo.

Ca and Mg are quite good at displacing the K and Sodium from their seats. So a couple of days feeding properly will tend to get the balance back where it works again.

When flushing CoCo a half strength feed is used. Even if it's the last 2 weeks and you won't recycle it. Because CoCo covered in just K and Sodium isn't good for the smoke.
 

star crash

We Will Get By ... We Will Survive
ICMag Donor
Veteran
so flushing with plain tap water is just spinning my wheels? does nothing?
 

f-e

Well-known member
Mentor
Veteran
Depends on the tap water. You could have a lot of calcium carbonate. Generally, you just don't flush CoCo as it messes with the buffering, which in turn can mess with the pH. There is no guaranty how when the water source is unknown.

Flushing at half feed, once joined by the CoCo's own additions, should leave a workable solution. It must be said that some people like to see their plants get ill before they chop them though. Perhaps driven by the fact it resembles a plant finishing naturally. We all have different goals. A paper last year said that flushing actually did nothing. Personally I have always gone with reduced feed in any medium, as processes can't continue with bits missing. Making a burn out unlikely, imo


EDIT: CoCo is a reusable medium. It's condition is best kept maintained, for the next crop
 

star crash

We Will Get By ... We Will Survive
ICMag Donor
Veteran
is there a difference between flushing / and trying to get a nice fade ?
 

Dropped Cat

Six Gummi Bears and Some Scotch
Veteran
A nice fade can be had by reducing feed rate in coco as well as timing of proportion of bloom/veg nutes,
but as many have said before, avoid a flush at 0.0 ec.

Temps/humidity, and distance of light from canopy, all have impact on the finished plant.

As I re use my coco, my goal is to have the plants finish in the pot of coco that is prepped for the next run.

Chopped plants also present a variable with duration pre jar, temps. and humidity.

See, its so simple, lol
 

.............

Active member
Any suggestions as to why my runoff is coming out so high after a week of PH’d water flush? Was almost 2000ppm when my feeds were 1200ppm at most.

You need a whole lotta run off is all.

What I've done:
feed to runoff, 20% runoff, managed salt build up etc.
Flushed down to <400ppm and plain water water until fade.
flushed plain water with and without pH correction.
Flushed and re-buffered used coco.

What I do now:
Never check runoff.
Never feed till runoff (500ml hand fed multi feed
Never flush, just plain pHd water until fade achieved.
Sift and reuse coco, no rinsing or rebuffering.

1200ppm/2.4 EC from clone to flower.
This is 1000PAR co2 enriched LED growing and is different using HPS. For an example you need to flush earlier or more under HPS compared to LED. LED fades out much faster.
 

hambre

Active member
is there a difference between flushing / and trying to get a nice fade ?

Why would you want the plant to fade? If you want colours, put the airco, but all plants do different. Flushing doesn`t work at least you want to save nutes, it has 0 influence on bud`s taste or production.
 

Sante

In DoPa
Depends on the tap water. You could have a lot of calcium carbonate. ...
hi man.
Which EC value of cal/mag solution or straight tap water do you consider "a lot" or at least enought for last weeks in coco without nutes?

What you meant by some peole "like to see their plants get ill"? Just extremely faded leaves?

... Flushing doesn`t work at least you want to save nutes..

It could be usefull also to avoid massive defoliation and let a selfprocess easiest and cheaper..perfect for lazy growers on a budget..and I personally love faded plant and autumnal colours...to me is quite hard to manage nutes and choose the right timing to get the better compromise.
 

f-e

Well-known member
Mentor
Veteran
Coco needs feeding lots of cal and mag to stay good. If your tap is about 0.5 that's quite a bit of calcium. I would still add some Mg though. You must keep it in solution to displace the K and Na from the coco. It's a constant cleaning process. Displacing them and taking their place.
Typically a flush is done with no less than half strength feed, but it''s a bit of a compromise to keep everyone around the table happy. The cal and mag shouldn't be reduced. Coco flushing is full strength to remove excess.
If you lower the ec, the plant will eat the buffering if it wants it. We don't want this. Recovery is slow.
 

Desert Dan

Well-known member
Veteran
So what’s the accepted practice for finishing in coco? Half strength EC last 2 weeks? RO with Camg or tap only? I’ve always heard straight RO for the last 2 weeks…

This is my first time running pure coco and I’ve already witnessed phantom EC loss early on from not properly buffering. Appreciate the input!

-DD
 

Ca++

Well-known member
Coco is constantly supplying K and Na, which it releases as it's a bio product, breaking down slowly. The stuff sourced from south america has less Na, as it's not all grown and processed by the sea.

We need high levels of Ca and Mg in coco foods, to clear this K and Na away. We are talking about the cec here, where the coco has a holding capacity, which would all become K and Na if left to chance. Interestingly, our plant will take Na when looking for K, and can actually use Na in place of K, up to about 70% of the total demand for K. Then it's dead. Before which, it gives a soft tissue growth, which doesn't gel well for mold resistance, or the stomata's abilities to let let the plant breathe.

While some coco suppliers look upon this decomposition to suggest you don't use it more than a few times, you really can if it's kept in good condition. It's best to just keep your coco a good living environment, as you would in soil/organic grows. If you do need to flush, following some total disaster, then Cal-Mag should be used, to get to half the EC of a full feed.

When people talk feedy weed, it's something like the 'snap crackle n pop' of K, which is quickly absorbed by plants. Or the chemical taste of P. Trying to flush coco, will just leave lots of K to eat. With little in the way of competition, or support elements to process it. You can't flush it out, as you just make the cec more K loaded, by lowering other things. The rate K is released from coco, is enough to make you wonder why they put any in the feed. It must be displaced, with Ca & Mg particular favourites for the job. Though if you want your plant to keep processing, not just accumulating, then you don't stop feeding anyway.

Most of the flushing we see, leading to colours such as Mn deficiency, are little more than starvation diets. Mistaken for the end of life effects seen in very mature plants. Plants which more and more people, are starting to recognise as undesirable. Based on the type of smoke they like, not being couchy.
 

flower~power

~Star~Crash~
ICMag Donor
Veteran
still bit confused about the best practice .not so much the why of it anymore. are you to feed Full strength right up to harvest? Does it matter? do you guys dial back at all? I’ve done every way possible I think I’m not sure if I have seen that much of a difference in the end product flavor wise…My indoor never taste as good as it should ..In coco
 

Desert Dan

Well-known member
Veteran
Coco is constantly supplying K and Na, which it releases as it's a bio product, breaking down slowly. The stuff sourced from south america has less Na, as it's not all grown and processed by the sea.

We need high levels of Ca and Mg in coco foods, to clear this K and Na away. We are talking about the cec here, where the coco has a holding capacity, which would all become K and Na if left to chance. Interestingly, our plant will take Na when looking for K, and can actually use Na in place of K, up to about 70% of the total demand for K. Then it's dead. Before which, it gives a soft tissue growth, which doesn't gel well for mold resistance, or the stomata's abilities to let let the plant breathe.

While some coco suppliers look upon this decomposition to suggest you don't use it more than a few times, you really can if it's kept in good condition. It's best to just keep your coco a good living environment, as you would in soil/organic grows. If you do need to flush, following some total disaster, then Cal-Mag should be used, to get to half the EC of a full feed.

When people talk feedy weed, it's something like the 'snap crackle n pop' of K, which is quickly absorbed by plants. Or the chemical taste of P. Trying to flush coco, will just leave lots of K to eat. With little in the way of competition, or support elements to process it. You can't flush it out, as you just make the cec more K loaded, by lowering other things. The rate K is released from coco, is enough to make you wonder why they put any in the feed. It must be displaced, with Ca & Mg particular favourites for the job. Though if you want your plant to keep processing, not just accumulating, then you don't stop feeding anyway.

Most of the flushing we see, leading to colours such as Mn deficiency, are little more than starvation diets. Mistaken for the end of life effects seen in very mature plants. Plants which more and more people, are starting to recognise as undesirable. Based on the type of smoke they like, not being couchy.
Thank you for the very thorough response!

In short, would you say tapering feed is the best option in coco? With a week of camg only water to finish?

-DD
 

Latest posts

Latest posts

Top