COCO COIR Coco question

[9fingerleafs]

Hello my fellow growers. I’m finally switching to coco. I bought a 230litters pack of coco fiber from a “natural” source, meaning it’s not branded and locally sourced. Anyway my question is should I rinse/buffer once or twice? In GWE says a quick 10 min soak it’s enough but I’ve seen other places say it needs two 8hours soaks in order to buffer correctly for cannabis. Also been thinking, is it a good idea to mix the 130litters of fox farm soil I got left with the coco?? If so what ph should I aim for? Thanks in advance

[Doubledealing72]

That's a good question about mixing it with soil. I've always just bought the coco that's ready to go in the bag. But from what I have read about the bricks, most videos I have watched say to do it for a long time.

I would go with the 8 hours and make sure to put plenty of CalMag in it to precharge it with. Otherwise the coco will take it all and not give the plant enough. I give CalMag with every feeding and it doesn't seem to hurt them.

Coco is awesome. I tried dwc at first and got root rot. Switched to coco and never went back.

[9fingerleafs]

Yeah I think I’m gonna do first a 8hour soak with my 1.4EC deep well water and then another one with ro water and calmag. That way I don’t waste nutrients

[DrPhoton]

Are you going to use perlite as well ?

If your wanting to do full hydroponics then its not a good idea to mix with soil. Mixing with soil, looses some of the benefits that coco and perlite offer. However many people use soil and then apply amendments such as coco and perlite, to allow better drainage and air availability to roots.

I have switched to 50/50 coco perlite mix this grow, with daily fertigation. And i will never go back. The consistancy of development seen with this has been great.

[9fingerleafs]

I actually didn’t thought about that. Now that you mention it I should get some perlite. I think I’m gonna keep separate my soil from the coco and that way I can even do a side by side with clones to really see the difference.

[DrPhoton]

Yea give it a go.

With regards to buffering coco, the idea is to fill as much of the cation sites as possible, due to the natural tendancy for coco to leach cations such as calcium and magnesium from the nutrient solution. Unbuffered coco, can create cal-mag deficiencies as these nutrients are made unavailable to the plants as they are held too strongly by the cation sites.

Coco naturally has lots of sodium and potassium, so a initial flush with low EC water is recommended to release some of the sodium in the media. The rinse is also important for ridding the fine particles from coco, which creates further problems by increasing the available cation cites. Which is what we are trying to avoid in coco, we want as inert media as possible. Making the nutrient solution we provide, as the main source of nutrients.

You then want to buffer coco with calmag, to release the left over potassium and replace with cal-mag to prevent the stripping of these minerals from the nutrient solution as previously discussed. The amount used is typically around 200-400ppm or 0.1-0.2 EC. You want to buffer the coco for at least a few hours, with thorough mixing to expose new cation sites to the cal-mag. This can be repeated by rinsing the coco again to drain off the potassium released during the first buffer and then repeating the process again. Two 8 hour buffers should be plenty, but you can get away with just a single buffer for a few hours.

During the grow, the coco will still want to strip some of that cal-mag, but it will be much less compared to unbuffered coco and you will not have to use as much cal-mag.

[DrPhoton]

Yes more detail will be great. Im am genuinly interested. I have pretty deep level understanding in plant biology and other fields. So complexity is nothing new to me. I have researched enough to understand the basic principles in soil biology. But nothing major, major textbooks on plant biology typically dont go into much detail.

Based on your previous comments, were you suggesting that the EC i suggested to buffer with is too low ?. I wont argue that as i buy product thats pre buffered so this was only an assumption. So to also be clear, you also say that the required amount of calcium to buffer with is dictated based on the volume of media. So the EC required will be dependent. ?

Whats most interesting is that you suggest buffering is practically ineffective when done for less than 24hrs ?

Good to know that rinsing does leach out certain minerals well. I wondered whether it did anything.

I have seen that some coco can be very dusty, with large amounts of fine particles. Using the right mesh filter, this peat can be removed. Which would be beneficial IMO.

[9fingerleafs]

The water turns brown very quickly and a fine dust goes tru the fabric and ends up in the bucket. I can only assume all kinds of things are being flushed. I don’t know where the coco came from. But I know I will dump the finest dust that sank to the bottom and use only the top 4/5ths of quality fiber. When I rinse. Should I flush until the runoff is not dark brown??

[Iammygod]

100g dry coco heavily loaded with 0.85-2.36mm particle size with very litte fine particles absorbs water 7 time of its weight, reaching 1.4L when it is saturated(So Water holding Capacity of this media is 50%. Good to know that 75-50% of this WHC is plant unavailable water; PUW). Lets say Cation Exchange Capacity of this media is 50 meq and Anion Exchange Capacity is 0. Potassium, Sodium, Calcium and magnesium in the CEC are 45%, 15%, 0 and 0 respectively. The solution i use for veg has the composition of 5 meq/l Calcium(100PPM), 3 meq/l Magnesium and 2.0 meq/l Potassium. So total cations are 10.0 meq/l. If i use this solution to hydrate dry coco, Cations start to exchange but No cation can exchange without reaching the surface of the particles of the media. So this equilibrium needs time specially at lower "temperatures and concentrations". At the beginning there are 3.5meq Calcium, 2.1 meq Magnesium and 1.4 meq Potassium in 0.7L water that our sample can hold. these are 7.0 meq cations. Here cation exchange sites can hold (1 - 7.0/57) of the total specific cation in the volume. This means 12.2% of tottal specific cation within the volume will be remain in the solution and the rest will be positioned in the CEC sites.
If we do some mathematics we get 3.5, 2.1, 23.9 and 7.5 meq Calcium, Magnesium, Potassium and Sodium respectively in the volume and 12.2% of these are 0.43, 0.26, 2.94, 0.92+ 2.4 meq of the other cations, including Hydrogen ion, that remain in the solution.
Although we started with dry coco(hydrated coco contains water so it can't hold all of 0.7L) and higher Ca ratio in solutions compare to solutions formulated for low CEC substrate, these numbers and simple model show that chemical properties of the unbuffered coco needs to be fixed before planting unless we have a nutrient solution composition that formulated to work at that circumstances.

Any change in solution composition effects CEC sites. These changes in CEC sites need time depending on both temperature and concentration as i said. 24H sounds enough even at 20°C and concentrations as low as several times of that is used for feeding plants But the EC is not the correct quantity to know whether it's enough to shift Cations ratio within the media or not. You have to look at the number of cation moles you have in the solution not just EC.

[Mr.furley]

After I rehydrate with ph water or if im using permixed coco, I Just put my coco/perlite in a 5 gal smart pot and run 2 gallons of ph 6.2 water with calmag through the pot like a flush.
Done.

There is a different in Coco.
Inland coco (not grown next to the sea) does not contain the salt content that, Coastal grown coco would. So it is worthy of checking were it was grown if you can.

I have amended Coco with soil before, work great for what I needed, didn't have Liquid Fertilizer till flowing and it got my there. I Ph'ed my water at 6.5.

good luck 9'

[9fingerleafs]

thanks furley, will check that

[DrPhoton]

100g dry coco heavily loaded with 0.85-2.36mm particle size with very litte fine particles absorbs water 7 time of its weight, reaching 1.4L when it is saturated

Isnt 7 times 100g 0.7 litres ?? As water weight is 1/1 with volume.

(So Water holding Capacity of this media is 50%. Good to know that 75-50% of this WHC is plant unavailable water; PUW).

Yes, so from memory the water availability to plants is determined by the difference in field capacity and the wilting point. Can you provide data that shows this characteristic of coco coir ?

Lets say Cation Exchange Capacity of this media is 50 meq and Anion Exchange Capacity is 0. Potassium, Sodium, Calcium and magnesium in the CEC are 45%, 15%, 0 and 0 respectively. The solution i use for veg has the composition of 5 meq/l Calcium(100PPM), 3 meq/l Magnesium and 2.0 meq/l Potassium. So total cations are 10.0 meq/l. If i use this solution to hydrate dry coco, Cations start to exchange but No cation can exchange without reaching the surface of the particles of the media. So this equilibrium needs time specially at lower "temperatures and concentrations".

You say that cations start to exchange with hydration but no cations can exchange without reaching the surface of the particles of the media. This is not making sense to me and sounds a little contradicting. Care to elaborate ? Are you suggesting that cations initially start to exchange, but takes time for the cations to interact with exchange sites. Does this time factor have anything to do with the water potential through the media? Or is it simply the characteristics of adsorption.

At the beginning there are 3.5meq Calcium, 2.1 meq Magnesium and 1.4 meq Potassium in 0.7L water that our sample can hold.

You now say 0.7L so i assume it was just a error.

These are 7.0 meq cations. Here cation exchange sites can hold (1 - 7.0/57) of the total specific cation in the volume. This means 12.2% of tottal specific cation within the volume will be remain in the solution and the rest will be positioned in the CEC sites. If we do some mathematics we get 3.5, 2.1, 23.9 and 7.5 meq Calcium, Magnesium, Potassium and Sodium respectively in the volume and 12.2% of these are 0.43, 0.26, 2.94, 0.92+ 2.4 meq of the other cations, including Hydrogen ion, that remain in the solution.

Yes i seem to understand you here.

Although we started with dry coco(hydrated coco contains water so it can't hold all of 0.7L) and higher Ca ratio in solutions compare to solutions formulated for low CEC substrate, these numbers and simple model show that chemical properties of the unbuffered coco needs to be fixed before planting unless we have a nutrient solution composition that formulated to work at that circumstances.

Yes, i assume the nutrient solution for the circumstances you speak of where coco is unbuffered, would be that where the feeding solution compensates for the cations lost to the coco. So in other words, you not only feed your plants, but also your media (coco) as it would take its share of the available nutrients (mostly calmag due to their higher affinity with cation sites).

Any change in solution composition effects CEC sites. These changes in CEC sites need time depending on both temperature and concentration as i said.

So the quantity of solution used can change the time that cations take to adhere ?. What formula or data can you provide that shows how long a certain application would take. For what reasons do these factors have an effect on time.

24H sounds enough even at 20°C and concentrations as low as several times of that is used for feeding plants But the EC is not the correct quantity to know whether it's enough to shift Cations ratio within the media or not. You have to look at the number of cation moles you have in the solution not just EC.

So are you saying that the quantity of cation sites (which can be calculated by the volume of coco), dictates how much nutrient solution is needed for appropriate buffering. And also that the EC is not a ideal quantifier. As just as you previously stated, a single drop can be 400EC. But you need to calculate by quantity of cations within a solution and not by concentration (quantity vs concentration basically).


Overall i believe i understand what you are saying. And i must thank you for taking the time to do that in such a way that made sense. Hopefully you can extend on this with the further questions i have provided. I am very excited ^.^

[Iammygod]

● Yes. 0.7L
● 50-75% is what i had found in web before. I've never measured PUW of my own coco but i know water availability effects nutrient availability. So i water before the weight of the pot reach 60% in veg when plants are big enough and 75% in the heavy flowering. We may find some data at medteknutrients.com.au. I'll check later for you if you request.

● Cations in the solution, not just initially, but always and always exchange with CEC sites back and forth. The exchange rate decreases as exchange progresses. So we need time to reach equilibrium. We are talking about buffering, Why do we have to ask about water potential?

● 100g dry coco absorbs 700g(0.7L) water to reach 1.4L hydrated coco with Reletive density of 0.57. I found no error.

●

● Lost and gained

● Too complex to find a formula. Yes, Temperature and concentration effect rete. And time requirement depends on rate.

● Yes; 400PPM. We all here to ask and learn.

[DrPhoton]

Ah yes yes. Thanks again, this was very helpful. In the future i may poke your brain again but for the time being this has been plenty.

[DrPhoton]

The water turns brown very quickly and a fine dust goes tru the fabric and ends up in the bucket. I can only assume all kinds of things are being flushed. I don’t know where the coco came from. But I know I will dump the finest dust that sank to the bottom and use only the top 4/5ths of quality fiber. When I rinse. Should I flush until the runoff is not dark brown??

Yes flushing the finer particles of coco peat is beneficial, so flushing until clear (indicating that most of the peat that can be leached has done so) is good. I think you will have satisfied the coco enough after what you have done

[9fingerleafs]

After 24 hours soaking I rinsed like campesino suggests in his video with a metal pasta strainer and removed all peat, I left the coco soaking one last night. I figured I can’t over do it right?? Thanks a lot dan, have a wonderful Sunday. I’ll keep you posted

[DrPhoton]

Yea exactly. You too man, ima watch the boxing soon ^.^ go wilder.

[9fingerleafs]

A little update. Popped 5 seeds and placed in solo cup with coco

[9fingerleafs]

Update, seedlings looking a little light but very healthy

[DrPhoton]

Cool cool. Theres so many types of coco isnt there. Mine is a much finer grade compared to yours. Yours is very stringy/barky. But im sure its fine.

[9fingerleafs]

Yeah maybe a rinsed too much, I chose the 70% peat and 30% fiber but after all that soaking and rinsing only fibers remain, I’ll have to do a side by side in the future with the peat and without it

[DrPhoton]

Yea that would be interesting to see.

[9fingerleafs]

Just a little update, transplanted 5 seedlings into one quart containers and he first 3 clones went into solo cups with coco as well. I also added the perlite

[9fingerleafs]

3 of the seedlings looking fantastic, one not so much, and the little tint on the bottom

[9fingerleafs]

A little update on those seedlings. Still in one quart containers, seems like they’ve developed lots of roots and started taking nutrients, color is better also, getting darker every day

[9fingerleafs]

These are being grown next to the window, and 14watt cfl at night

[9fingerleafs]

ANother update, this is day 19 I think, roots are growing fast

[9fingerleafs]

Also I top/fimmed

[DrPhoton]

Nice, they looking very healthy.

[9fingerleafs]

It’s day 22 for the seedlings, two of them are ready for transplant. I made medium size bags out of black garden fabric. I think between 2-3 gallons

[D.A.A.S.69]

Very nice indeed.

[9fingerleafs]

Thanks my good friend. I kinda was a bit afraid this not branded not buffered very fiberous coco wasn’t gonna work but it does a pretty good job I’m soaking the next batch already, I got 7 clones in solo cups wanting a transplant too

[9fingerleafs]

Plants are doing absolutely fantastic. Big fat healthy leaves. One of them has a small mutation, instead of preflower it’s growin a leaf

[Tika]

I am sooo friggin late to this thread...just found it! My Bad. If you still have questions I am formally opinionated on the subject. If you want to yak on it PM me and/ or I’ll send contact info.

[9fingerleafs]

thank you tike youre so kind as for right now everything is going smooth but i wont hesitate PM you at the first sight of trouble. im falling in love with coco, just a pain in the ass to hand water 15 plants everyday

[Tika]

I have never fed/watered. Every day. Every 3rd day. ..start to finish.
Your plants look great. What size pot in now? Same?
Anyway ...don’t hesitate...before problems😜

[9fingerleafs]

this are in DIY fabric pots, i think maybe 2 or 3 gallons, im planing on buying 5 or 7 gal pots, i water daily cause my coco isnt as fine grounded as some, it has big fibers that hold even less water