Vapor Pressure Deficit - Basically it's a measure of temperature and humidity with relation to their effect on transpiration. Many gardeners use a low RH which can cause stress without equally low temperatures. Most gardens should be working with their RH in the 60% to 70% range but many people are down under 40% because of mold issues.
Cation Exchange Capacity - "Some coirs have been chemically treated, this is most often the case with loose pre-hydrated varieties versus compressed blocks. The treatment has been done to satisfy the cation exchange capacity (CEC) of the growing media. As a refresher, “cations” are positively charged ions, such as Calcium, Magnesium, Sodium, and Potassium. This means that the growing media will hold these ions in a matrix, releasing them as required by plants. There is one slight drawback to this. Until the cation exchange capacity of the growing media is filled, the growing media may hold positively charged nutrient ions, most notably calcium, in reserve, making them less available to plants. However, the cation exchange capacity (CEC) of the coir media is quickly filled, and actually assists calcium absorption in the crop cycle. To ensure optimum availability of all nutrients, supply additional calcium during the first week of growth or during the hydrating process of the coconut coir. Calcium supplement products are ideal for this. Some nutrients specifically formulated for coco tend to have elevated levels of calcium and magnesium while having lower levels of nitrogen."
Enh, The stuff is like $0.15 per liter for me, most people can get it for about x2 that price, which still isn't all that bad in the grand scheme of things. Almost all coco comes from Sri Lanka, and a distributor out there. I don't know of any hydroponics company that actually owns a tree or processes everything themselves from husk to bag. Most of the difference between brands come with how they are treated by the manufacturer. I like the Cocogro because it's been steamed and cleaned and compressed. Compared to unsteamed brands like CANNA I've found less debris and bug issues, but that's not 100% universal. The coir depends on the monsoon seasons to rinse it clean and break it down prior to shipping, so even from year to year you could find a reputable brand is suddenly garbage, but the less reputable brands are still selling the good "old" coco while it lasts. I kind of rely on some form of consistency from my brand because of the nature of the coco and steaming it seems to provide a similar product for me time after time.
I've used saucers and tables mostly. I went out of my way to accommodate runoff but it's not in the cards for everyone.
You got it. Technically, what we are doing is converting the percentage into mg/L=ppm. The 2.65 is a simple reduction of that formula (X%/100)*(1000mg/Yml)*(3.78L/1gal).
For Calcium and Magnesium you'll use the same as N. I think Suflur is represented in a funky way, but the plant uses that form of sulfur (or something like that, I've never really worried much about it). Apparently, 60 to 120ppm of Sulfate during flowering is recommended.
The same way, but you're using grams instead of ml. I use a rough estimate that 1 tsp ~ 5 grams. None of this is an exact science, I just use the numbers as a comparison so that I know MY "78ppm" of Nitrogen from a specific system is either too much or too little for MY plants. As far as another grow, with a different nutrient program, and different plants, it can be difficult to get specific. I just keep an eye on things until I have an idea of what's going on.
Yup, Just CNS 17 Ripe and the CES Uncle Johns blend until plain tap water feedings over the last 7 to 10 days.
Totally optional, especially outside of organic mixes.
If your root zone temps are ok then the lockouts are caused by that insane ec they are living in as you probably already know. Not much you can do except flush it down to an acceptable range. I learned my lessons, I stay in nothing larger than 2gal fabric pots with 100% coco and never go above 1.0ec in veg and 1.2ec in bloom. Up to 6' trees. Goodluck with the flush.
