Yes - following the thread here. I too had done some study of terra preta over (last) winter with the help of a bryologist (Rick S.) who had contacted me. He sent me a bag of the product that was supposed to be manufactured in similar fashion to the original method. I might be getting my facts a little skewed here, but I believe it had been made to fill a specification for use in water filtration for a city in OH. I did pot several plants in a kind of experiment with a loose control, but I was so busy this summer I lost track of what I was attempting to evaluate, so cannot report first hand. I can say though, that I use horticultural charcoal in plantings where the plant prefers a wet soil or in plantings where I allow the plant to stand in water to satisfy its thirst. If you're asking what to do about your coir-containing soil, I can't help. I have also been sent chc's for evaluation, which I'll do in the growth cycle subsequent to spring repot time, but haven't used the coir. I confess to being somewhat skeptical that it will outperform peat in the mixes I use, but I also like to think I am open minded enough to transition to it, should it prove valuable. I have no opinion on the validity of the U of U study, but I know I will be watching closely for evidence that there might be a problem when using coir. I probably should read the study again, to see if this is covered, but one thing I might note about any soil that holds high volumes of water is that low oxygen levels cause iron and manganese to become electron acceptors. This leads to their precipitation (iron and manganese) and, even though these elements might be present in soils, the plants inability to assimilate them. Either elemental deficiency will cause the chlorotic effect and certainly, because Fe is instrumental in the maintenance of chlorophyll, it will influence growth. What does all this mean? I suppose I would be very careful about watering practices when using coir. My observations are completely unfounded, so I would have to defer to any experienced grower if their experience is a + one until I have an opportunity to develop an opinion. Al

Nice to see another zone 8 coco grower. What part of zone 8 you in? I'm in Waco, TX From what I've read, the number 1 reason people have problems growing in coco coir is they treat it like soil. Coir is a hydroponic medium, and should be treated as such. I have 5 pepper plants and 1 cherry tomato plant on the patio growing in coco coir / perlite mixed about 7:3. I'm currently hand watering every day or every other day, using Hesi coco nutrients (a 1 part fertilizer designed specifically for growing hydroponically in coco). I feed 12 ml of nutrient mixed with 4 L of water, pH'd to about 5.8 The trick is to feed until you have run-off (approx 10-20% of what you watered should run out the bottom). Never let it dry out. Watering til that much runs out does two thing: 1)flushes the medium with every watering, preventing build up in the medium. 2)ensures you maintain a fairly consistent level of nutrient in the medium. Fluctuations in ec/ppm & pH = no good. I was a little leery at first to water that much. I was always told too much water is the most common mistake people make. Well, with coco, forget all that. The more often you water, the better off you'll be. Since the coir is so coarse, it will always have plenty of oxygen trapped inside, unlike most mediums that become water-logged and drown roots.

Sphagnum peat and coir have nearly identical water retention curves. They both retain about 90-95% of their volume in water at saturation and release it over approximately the same curve until they both lock water up so tightly it's unavailable for plant uptake at about 30-33% saturation. Coir actually has less loft than sphagnum peat, and therefore, less aeration. Because of this propensity, coir should be used in mixes at lower %s than peat. Because of the tendency to compact, in the greenhouse industry coir is primarily used in containers in sub-irrigation (bottom-watering) situations. Many sources produce coir that is very high in soluble salts, so this can also be an issue. Using coir as the primary component of soils virtually eliminates the reasonable use of lime or dolomitic lime as a Ca source because of coir's high pH (6+). Gypsum should be used as a Ca source, which will also help eliminate problems associated with coir's low S content. All coir products are very high in K, very low in Ca, and have a potentially high Mn content, which can cause antagonistic deficiencies and interfere with the uptake of Fe. I haven't tested coir, but I have done some testing of CHCs (coconut husk chips) with some loose controls in place. After very thoroughly leaching and rinsing the chips, I made a 5:1:1 soil of pine bark:peat:perlite (which I know to be very productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6 cuttings of snapdragon and 6 cuttings of Coleus (each from the same plant to help reduce genetic influences) in containers (same size/shape) of the different soils. I added dolomitic lime to the bark soil and gypsum to the CHC soil. After the cuttings struck, I eliminated all but the three strongest in each of the 4 containers. I watered each container with a weak solution of MG 12-4-8 with STEM added at each watering, and watered on an 'as needed basis', not on a schedule. The only difference in the fertilizer regimen was the fact that I included a small amount of MgSO4 (Epsom salts) to provide MG (the dolomitic lime in the bark soil contained the MG, while the gypsum (CaSO4) in the CHC soil did not. This difference was necessary because of the high pH of CHCs and coir.) for the CHC soil. The results were startling. In both cases, the cuttings grown in the CHC's exhibited only about 1/2 the biomass at summers end as the plants in the bark mix. I just find it very difficult for a solid case to be made (besides "It works for me") for the use of coir or CHC's. They're more expensive and more difficult to use effectively. The fact that some believe peat is in short supply (no where near true, btw) is easily offset by the effect of the carbon footprint of coir in its trek to the US from Sri Lanka or other exotic locales. That's the view from here. YMMV Al

TheMasterGardener1 Coco coir is pH neutral when used by itself, and wont affect pH in hydroponics. Peat on the other hand is another story. Peat can and will change your pH, and how much depends on the type and how much the peat is used. However I think sorghum peat moss is the most pH neutral, and really the only thing that should be used in hydroponics (but not cost effective). Most peat will absorb to much water, and compact, suffocating the roots. Bottom line, I would never recommend using a coco coir/peat mixture to grow hydroponically. But coco coir/chips is the growing media I prefer to use myself. Though it's typically recommended to test pH before adding nutrients to the water, it's rarely needed to be adjusted before if your using a good water source to begin with. Unless it's above 7, or below 5, I don't bother to pre-adjust pH (I know my water supply and don't even bother pre-testing it anymore). Any good nutrient manufacture will add pH buffers to the nutrients. The buffers will help inisionally adjust the pH, but their mainly their to help keep the pH stable (typically for about two weeks depending on your particular variables). You should never add lime or any additive to the growing media or nutrients indiscriminately. Doing so can lead to toxicity. Any good manufactured nutrient solution will already be a balanced nutrient. Adding extra mineral elements just because you have them lying around will change that well balanced nutrient. If your going to add an additive, be sure it's necessary before you do. Or at least make sure you can undo it if you don't get the desired results. Also by adding lime to the growing media in a hydroponic system, that will continually change the pH with every water cycle. Not a desired effect in recirculating hydroponic systems. The idea is to keep pH as stable as possible, not have it keep changing all the time.