Hi
With my coco I water
my seedlings once every two days until roots appear outside of the small coco coir cups
after transplanting
1st week [veg] > once a day
2nd to 4th weeks [veg] > twice a day
5th to 8th weeks [flower] > three times a day
after that four times a day
I drip in a recirculating system for 30 mins at a time, through 2l/hour drippers
this is in 6.5 litre pots, 20x20 x 25 [d]
This creates more than 10% runoff.
It works like a charm.
"Usually the idea behind the 10% runoff theory is that eventually the roots which would occupy most of the pot, would use up the moisture in the pot then wick the 10% runoff up and use that up too.
But if your plant is still a seedling and only occupying the top 20% of your pot then the wicking affect doesnt really work that well. In the meantime if there is so much moisture in the top half of the pot, then the roots will accumulate there and not go deep into the coco." - jonus
I disagree. I think your statements apply to soil. My roots go all over the place very quickly. And I'm sure wicking isnt such a good idea with coco, if you soak the medium regularly without making the runoff available to wick then there should be no need for that extra wicking water, which I think messes with the amount of oxygen being drawn down through the medium each time you water.
I believe the idea behind watering with a small amount of runoff is NOT to encourage roots to grow downward, though that might happen too I guess.
Because of this
"Coir has a very strong cation exchange ability, which means it can hold and release nutrient elements based on the plants needs."
watering to runoff introduces nutrients to the medium which replace some of the nutes left in there from the last watering, balancing the proportion of nutrients, and flushing out any high concentrations, preventing any undesirable nutrient build up.
"i "always" allow 10-15% run-off. the reason for run-off is to keep nutes from accumulating in the coco. every time you feed, you're in essence doing a flush" -silky
Yeah, keep watering with a small amount of runoff for the whole cycle, would be my advice, and let that runoff drain away somewhere, either to waste or into a reservoir to recirculate.
I read somewhere on here that because coco is so capable at holding oxygen, and because it is like a sponge, the water is distributed pretty evenly throughout the whole medium, so the roots keep searching for water at a faster rate than in soil, even when all the coco is wet. Seedlings dont need much water but with coco its very hard to overwater.
I wouldnt drip/water constantly through coco, like with clay pebbles for example, but a regular schedule works fine. My coco is pretty much constantly wet everywhere except the top 1cm, and no problems whatsoever, the opposite in fact, huge, gorgeous plants.
In short, dont worry about it being too wet, worry about it getting dry, water small amounts regularly, keep watering to runoff, and keep the drainage set up you got going. Only with soil do you need to know when its time for them to get water; with coco, if you stick to something vaguely like the feeding schedule I use you dont need to check the coco with finger or metre, or guess the weight of the pot, or look at the plant for clues. No worries about over or under watering whatsoever.
ps canna coco is awesome by itself
I really recommend hesi nutrients, though I havent used canna A+B
consider investing in an automatic irrigation + reservoir system, so you can automate the feeding. simpler and cheaper than it sounds, basically just a box, a pump, a timer and some pipes. Then you only need to mix the nutes once a week, and at the end of flowering you can water loads [like four times a day] without any hassle at all, which the plants love.
good luck, and have fun! coco rules!