What’s up DGC hommies!! Thanks to Jmystro for the inspiration…I did a thing. I built this automatic irrigation system using mostly parts that I already had, all I really needed to buy was the spikes that coming to the Coco. But now I have a few questions but I was hoping you could shed some light on. When I was hand watering I would water to 20% runoff and allow the pots to dry slightly more than 50% before watering again. I’ve heard a couple School of thoughts in regards to watering frequency. Some water daily, some water multiple times per day. What type of schedules do you guys use? I understand that if I increase my watering frequency I need to lower my ppm’s. What’s the best way to dial in my system? Should I still continue to water to 20% runoff? If there’s any cool tips or tricks you guys would like to share with me that would be great since this is my first foray into an automatic irrigation system. Thanks for the motivation Jmystro.
Root mass and pot size determine how often you should irrigate. You want your roots to search for moisture and minerals initially. Any oversaturated medium will slow root growth. I’ll explain the difference between top feeding and bottom feeding. I’ll also go over how I feed my clones once they’re rooted and ready for transplant all the way to harvest. First I’ll talk a little about mediums. Coco is a happy medium between living soil and something like rockwool in terms of ion exchange. Living soil has a high CEC, coco has a medium/low CEC and rockwool has no CEC. You can get away with feeding an inert soil hydroponically once a week and coco every few days, while rockwool needs minerals fed daily/hourly. This has to do with the mediums ability to hold onto minerals. Rockwool has no ability to hold onto and transfer minerals through ion exchange. This is why rockwool growers like The Capn feeds his plants multiple times a day at 15 minute increments. The roots need to be submerged in solution for ion exchange. Hand watering rockwool is futile and doesn’t offer much ion exchange. This is why using perlite in coco is pointless. Not only because coco has optimum drainage, oxygen and moisture levels. Like rockwool, perlite is inert and offers no CEC. The last thing I want to do is limit my coco’s cation exchange capacity.
Before I go into different feed schedules, I want to discuss the environment first. The environment plays a huge role in how your plants uptake water and minerals. Conditions in the room will determine how often they need watering also. The medium and solutions pH also plays a role. The warmer the room, the more the plants will drink. High humidity also plays a role in putting pressure on the stomata limiting the uptake of water from the roots. Too low humidity doesn’t put enough pressure on the stomata causing the roots to constantly uptake water to keep the plant cool. We want balance. pH only affects the plants ability to uptake minerals, not moisture. Plants will drink water even with no minerals available. The health of the roots comes before anything else. I can chop off half the vegetative growth with minimal stress. That much stress to the roots would kill her most likely.
My focus initially is on root growth and vegetative growth comes secondary. I’ll take my rooted clones and transplant them into small pots. I’ll feed them a nice even npk with about 300-500 ppm along with some Recharge right after transplant day 1. Add a bit of rooting hormone (IBA) to your solution and roots will explode in the coco that first week. I’ll add Recharge to every feeding the first two weeks until they are fed daily. Then I go to once a week Recharge treats. I’ll wait 3 days and feed them again. I’ll then wait another 3 days before feeding them. This gives them enough time to fill the small pot with roots that first week. The second week I’ll feed them every other day. After the first two weeks the plants should be well established in their initial pots and are ready to be fed daily. Depending on pot size you might need to transplant again. You want at least one gallon of medium for every month the plant’s in the container. A half gallon pot is only good for 2 weeks before she’ll get root bound and stunted. A plant left too long in a container becomes worthless real quick and should be killed.
Daily irrigation schedules will be determined by a few factors. You a least realize the ppm needs to be lower the more times you feed. I’ll explain why when I compare top and bottom feeding. However long you plan to veg a plant should determine what size container to use and how often It’ll need feeding. A plant vegged for 2 months and then flowered for 2 months needs at least a 5 gallon pot. A plant flowered straight from a clone may only need a 2 gallon pot. The smaller the pot, the faster I’ll dry out allowing for more feedings. A large pot with a small root system will not drink near as fast, limiting feedings. Once a plant is about 3 weeks old regardless if they are still vegging or in flower, I feed them once a day. Two hours after lights on. Plants don’t uptake minerals when they are sleeping. It takes about two hours to fully wake up. Depending on pot size and root growth, by the 4-5th week of their life, I can start feeding them twice a day. Their second feeding comes halfway through their light cycle. The only reason to feed them 3 times or more a day in coco is if you are running them in small pots. Like a plant that’s alive for 5 months in a 2 gallon pot.
I’ll explain the pros and cons between top and bottom feeding coco. My first experience with coco was in 2001 with Canna Substra drain to waste. I’ve been a coco fan since. When you feed from the top you create a vacuum so to speak. Pouring solution through the medium brings in fresh minerals and oxygen from the top while removing excess salts left over out the bottom. Always water to run off. This is why drippers are bullshit. They deposit minerals without run off. The more run off the better. 20% minimum. It’s incredibly difficult to over saturate coco when top feeding. One negative aspect of top feeding is money. Irrigation costs time and money to set up. Drain to waste is recommended but you can recirculate your nutes. Performance goes down slightly when recirculating minerals due to their availability and ratios. Bottom feeding is possible but not recommended by companies like Canna. They don’t recommend bottom feeding because they want to eliminate user error. They won’t be blamed for our mistakes basically. I’ll explain why. Bottom feeding is easier and cheaper to set up. Especially when running large numbers. But there are some pitfalls to be careful of. Submerging coco holds far more solution than top feeding and can be bad for young roots to sit in. Nothing is flushed through when bottom feeding. Excess salts can build up quick creating an acidic medium if left unchecked. You need to do weekly plain water flushes before each res change to remove these excess salts. I recommend doing this even when top feeding. Why take a chance. We change our mineral ratios weekly for a reason. Don’t be the lazy fuck that leaves things to chance.
My God Jmystro, this is some gold info and I’d hate for it to be buried in the archives of a post.
I know you guys started logging all of the interviews to easily find, is it possible to create a space on the web for written knowledge like this? I could see a link for “First Time Growers” and this being a ‘Basics of growing medium and watering’ topic. Just a thought.
Much respect to Jmystro and the Dude Grows team!
#growerslove
Great post Jmystro. Getting ready to try coco for the first
time. Long time growing in soil only. Understanding the CEC of
coco is really helpful . I know a lot of peeps use the coco pearlite
mix and or layers for Hempy buckets. Seems like more pearlite,
more watering, more like passive hydroponics ? Please help me out
if I’m off target here.
Thanks- LB
Holy smokes you are the man maestro.
This is exactly why I love the DGC. J, your the man bro. Thanks for answering pretty much all the questions I have, even the ones I didn’t ask. I’ll go with four gallon containers cause I veg for about 45 days from seed. I’ll leave out the perlite next time. I had the pleasure of hanging with Chet from canna when he was here in the Philly area and he already spanked me for that! The system you recommended is working well and was a breeze to build. With my pump it takes about 3 minutes to get 20% runoff and I’ll adjust the feeding schedule to come on 2 hours after lights on. One question about nutrient Temps. My reservoir is outside of my tent on a concrete floor and is about 63ºf. It never goes above 68º even in the summer. 63 shouldn’t be too cold should it? Man, I’m having fun and keeping it as simple as I can. Canna a and b, recharge and mammoth p , p/K and boost during week 5ish. I do weekly foliars with boost as well. I really appreciate the time you took to type all that out and I think a lot of folks are going to learn a lot, like me!
#GrowersLove
Thanks SoCalDank, I’m actually pretty impressed with the site’s search feature. You can type in any word and find buried treasure.
Lord Blueberry, the only reason perlite is used in a hempy bucket is for a buffer between the nutrient solution and coco. You can use any fine material like growstones or crushed lava rock instead. The material needs to be fine enough to allow solution to wick up through capillary action. It’s only used to keep the coco from sitting in the nutrient solution.
Hey The Merry Dankster, glad to be of some help. 63 degrees is a bit cold. Not the end of the world bad but try putting something like a mat or piece of carpet under the res to get it off the floor. If you can keep it around 68 they’ll be much happier. Room temp will determine how much of a shock the low temps are in your res. If the room was 72 and the res was 63, it wouldn’t be as much shock than if the room was 80. It’s not a bad idea to cool the room down for those first two hours while they’re waking up. Like right at sunrise when it get’s a bit colder causing dew until the sun get’s high enough to warm up.
Thanks for the information. I grow in soil but I learned a lot from your comments! I’ve been thinking about growing in Coco but have my current grow in a light potting soil / compost mix available here on Oahu.
Thanks for the info about when to feed the plants. I usually feed the girls when I get home from work in the evening only about 1 1/2 hours before dark; looks like I need to change my routine.
Thanks 808Lathedog. If you’re only watering your plants in soil it doesn’t matter what time of day or night you do it. Feeding during their light cycle only pertains to using nutrient solutions in a hydroponic system.
Couple more questions if you don’t mind. So, why does the ph raise overnight. 5.8 when I mix and 6.1 the next morning. Also, I notice my ph up falls out of solution when I mix it. Never used ph up before but I don’t think that’s normal.
Great question Merry Dankster. Nutrient solutions go through chemical processes themselves. Never mix a solution and then immediately irrigate. It take’s several hours to stabilize. During this stabilization, potential hydrogen (pH) levels are also adjusting. This is when you should adjust your solutions pH. Not right after you mix your nutes. pH up (a base) is not near as strong as pH down (acid) and requires more base to raise the pH than an acid required to lower it. The ingredients and their ratios will cause initial pH shifts.
Awesome. I’ll make those adjustments. Thank you!!
I said God Damn, God Damn…
I pulled out my notebook and took 2pages of notes of this conversation entitled…
“Jmystro: On Coco.” lol…Brilliant mate.
Can i ask how you feel about amending coco? As scotty recommends on occasion to mix in 20% worm castings to the coco.
2) You Fuck With Biochar? Mr Real gots me thinkin couple weeks back on this topic in a coco amending talk he and the dude had.
Sure GRAMBO, I like to add some biologicals like fresh worm castings and Recharge of course. I like to think of microbes in hydro as little helpers. I might not depend on them entirely like in a living soil, but they can help hand me tools so to speak. It’s not a bad idea to add a little biochar when adding microbes. Bacteria shit acid and can lower the coco’s pH if you go crazy with them. The biochar will give the microbes a home as well as help raise the coco pH. They’ll both help buffer your grow from potential problems.
Great read, thanx Jmystro. It answered every question clearly pertaining to feeding/watering. Keeping this page qued up for further reference.