While fiber size is a factor in compaction this thread reaks of trolling. Just check out the "studies" Glow references when it's not "They."
(see Awang, Yahya and Shaharom, Anieza Shazmi and Mohamad, Rosli and Selamat, Ahmad (2009) Chemical and physical characteristics of cocopeat-based media mixtures and their effects on the growth and development of celosia cristata. American Journal of Agricultural and Biological Sciences, 4 (1). pp. 63-71. ISSN 1557-4989)
Problem statement: Cocopeat is considered as a good growing media component with acceptable pH, electrical conductivity and other chemical attributes [Agreed] but it has been recognized to have high water holding capacity [One of the good growing media criteria] which causes poor air-water relationship [by comparison to... what? This simply is not true and has no basis], leading to low aeration within the medium, thus affecting the oxygen diffusion to the roots [conclusion from a false arguement]. Incorporation of coarser materials into cocopeat could improve the aeration status of the media.
Approach: Selected chemical and physical characteristics of five types of growing media comprising of (v/v) 100% cocopeat, 70% cocopeat: 30% burnt rice hull, 70% cocopeat: 30% perlite, 70% cocopeat: 30% kenaf core fiber and 40% cocopeat: 60% kenaf core fiber were determined and their suitability as growing media was tested using Celosia cristata. Data on pH, Electrical Conductivity (EC) and various aspects of air-water relationships of the media, as well on growth and flowering of test plant and leaf nutrient contents were collected. [I cannot wait to see the data/numbers]
Results: Initial pH for 100% cocopeat and 70% cocopeat: 30% kenaf core fiber was higher than the other media [how much higher? 0.01 or 1.0, kind of matters] but the values were eventually similar by the end of the study. The bulk density and EC of media containing burnt rice hull was markedly higher than the other media (0.12 g cm3 and 0.48 mS cm-1, respectively). [So they added aeration material and made the media more dense] Media comprising of 70% cocopeat: 30% burnt rice hull and 70% cocopeat: 30% perlite contained higher air content [again... how much higher, why the omission?]. The former held the highest volume of available water. Incorporation of burnt rice hull and perlite into cocopeat increased water absorption ability of the media which reached saturation earlier than the other media. Addition of burnt rice hull (30%), perlite (30%) and kenaf core fiber (30%) to cocopeat elevated the Air-Filled Porosity (AFP) of the media [Great, tell me again by how much and why that much is valuable]. The growth and flowering of Celosia cristata were the greatest when grown in a mixture of 70% cocopeat: 30% burnt rice hull and perhaps linked with a good balance in the aeration and moisture relationship of the media [The greatest? were there more flower sites? How many more? More biomass? Dried? Height? Internodes? Stem width? Tensile strength? Opinions don't belong in the results. Results belong in the results] . Conclusion: Results of this study indicated that certain chemical and physical properties of cocopeat can be improved through incorporation of burnt rice hull and its positive effect was clearly reflected in the growth and development of Celosia cristata. [Conclusion: This is a bullshwice study we should scrutenize and not take at Glow's word to be mislead].
It can hold eight to nine times its own weight in water without becoming anaerobic-even when saturated it can still hold on to around 22% air-beating even rockwool (around 10% air holding capacity.) Coco coir is therefore a forgiving hydroponic medium, allowing roots access to enough oxygen even when watered a little too enthusiastically with a warm nutrient solution. This makes it the ideal choice for beginners!
At field capacity, horticultural perlite air-filled porosity is 27 %...
Just look at the numbers there. Coco=22% Perlite=27%
Yes, the Perlite holds more air than coco, and adding perlite to the mix will improve aeration. I don't think I can, or would, argue that. What I absolutely disagree with is that the addition of Perlite, without regard to any other factor than more frequently required feedings, would result in better growth in coco. I've been working in the stuff for going on 6 years now and none of my mixes can compare to using the correct amount of pure coco.
Having the right amount of coco, to match the size of the plant and the root mass, is what is important. The issue here is people are using containers that are WAY too big for the system they are in. Coco is not soil and should not be treated the same. Coco is a hydroponic media more similar to rockwool, in that: less media and root mass are required to support the same sized plant because the delivery of nutrition is much more efficient.
5 gallons of coco is going to drown a young plant. Absolutely, and that's when you'd need to cut it with perlite if you just HAVE to have a container that large. What I have learned is that when the container shrinks and the volume decreases the aeration improves and the watering frequency increases. Why pay more? Extra big container? Plus perlite? Not in my garden. Give me 1 gallon of pure coco in a 2 gallon Smart Pot and I'm off to the Easy Streets.
(see Awang, Yahya and Shaharom, Anieza Shazmi and Mohamad, Rosli and Selamat, Ahmad (2009) Chemical and physical characteristics of cocopeat-based media mixtures and their effects on the growth and development of celosia cristata. American Journal of Agricultural and Biological Sciences, 4 (1). pp. 63-71. ISSN 1557-4989)
Problem statement: Cocopeat is considered as a good growing media component with acceptable pH, electrical conductivity and other chemical attributes [Agreed] but it has been recognized to have high water holding capacity [One of the good growing media criteria] which causes poor air-water relationship [by comparison to... what? This simply is not true and has no basis], leading to low aeration within the medium, thus affecting the oxygen diffusion to the roots [conclusion from a false arguement]. Incorporation of coarser materials into cocopeat could improve the aeration status of the media.
Approach: Selected chemical and physical characteristics of five types of growing media comprising of (v/v) 100% cocopeat, 70% cocopeat: 30% burnt rice hull, 70% cocopeat: 30% perlite, 70% cocopeat: 30% kenaf core fiber and 40% cocopeat: 60% kenaf core fiber were determined and their suitability as growing media was tested using Celosia cristata. Data on pH, Electrical Conductivity (EC) and various aspects of air-water relationships of the media, as well on growth and flowering of test plant and leaf nutrient contents were collected. [I cannot wait to see the data/numbers]
Results: Initial pH for 100% cocopeat and 70% cocopeat: 30% kenaf core fiber was higher than the other media [how much higher? 0.01 or 1.0, kind of matters] but the values were eventually similar by the end of the study. The bulk density and EC of media containing burnt rice hull was markedly higher than the other media (0.12 g cm3 and 0.48 mS cm-1, respectively). [So they added aeration material and made the media more dense] Media comprising of 70% cocopeat: 30% burnt rice hull and 70% cocopeat: 30% perlite contained higher air content [again... how much higher, why the omission?]. The former held the highest volume of available water. Incorporation of burnt rice hull and perlite into cocopeat increased water absorption ability of the media which reached saturation earlier than the other media. Addition of burnt rice hull (30%), perlite (30%) and kenaf core fiber (30%) to cocopeat elevated the Air-Filled Porosity (AFP) of the media [Great, tell me again by how much and why that much is valuable]. The growth and flowering of Celosia cristata were the greatest when grown in a mixture of 70% cocopeat: 30% burnt rice hull and perhaps linked with a good balance in the aeration and moisture relationship of the media [The greatest? were there more flower sites? How many more? More biomass? Dried? Height? Internodes? Stem width? Tensile strength? Opinions don't belong in the results. Results belong in the results] . Conclusion: Results of this study indicated that certain chemical and physical properties of cocopeat can be improved through incorporation of burnt rice hull and its positive effect was clearly reflected in the growth and development of Celosia cristata. [Conclusion: This is a bullshwice study we should scrutenize and not take at Glow's word to be mislead].
It can hold eight to nine times its own weight in water without becoming anaerobic-even when saturated it can still hold on to around 22% air-beating even rockwool (around 10% air holding capacity.) Coco coir is therefore a forgiving hydroponic medium, allowing roots access to enough oxygen even when watered a little too enthusiastically with a warm nutrient solution. This makes it the ideal choice for beginners!
At field capacity, horticultural perlite air-filled porosity is 27 %...
Just look at the numbers there. Coco=22% Perlite=27%
Yes, the Perlite holds more air than coco, and adding perlite to the mix will improve aeration. I don't think I can, or would, argue that. What I absolutely disagree with is that the addition of Perlite, without regard to any other factor than more frequently required feedings, would result in better growth in coco. I've been working in the stuff for going on 6 years now and none of my mixes can compare to using the correct amount of pure coco.
Having the right amount of coco, to match the size of the plant and the root mass, is what is important. The issue here is people are using containers that are WAY too big for the system they are in. Coco is not soil and should not be treated the same. Coco is a hydroponic media more similar to rockwool, in that: less media and root mass are required to support the same sized plant because the delivery of nutrition is much more efficient.
5 gallons of coco is going to drown a young plant. Absolutely, and that's when you'd need to cut it with perlite if you just HAVE to have a container that large. What I have learned is that when the container shrinks and the volume decreases the aeration improves and the watering frequency increases. Why pay more? Extra big container? Plus perlite? Not in my garden. Give me 1 gallon of pure coco in a 2 gallon Smart Pot and I'm off to the Easy Streets.
