I prep my coco with reverse osmosis water PH'd at 5.8. Then i flush the bitch out of it with PH'd water as well. but then the run-off will measure about 6.2 - 6.3PH? WTF About a week later, after watering the plant three times with PH 5.8 water, the run-off measures between 6.5 - 7! The only way i have thought of rectifying this is by prepping the coco with water with a lower PH than 5.8. Can someone please help? How do you fix your PH problems with coco?
easy fix, you need more runoff, just water more. the fresh nutes will push the old nutes out that have the spiked ph.
Are you using ph'd water or a nutrient mix? The coco will retain nutrients giving it the proper ph, but if you are just using water then you are washing out any nutrients that might have been in there, thus raising the ph to that of h2o, hence the 6.5 to 7 ph.
fill the pot till the water is about an inch over the soil and then drain it all out that will flush your soil, your ph is high more than likely because of over fertilization, the nutes are excessive in the soil and thats why your run off is coming out high. or depending on how far you are into the grow it could be a salt build up either way flush the soil.
so should i just flush it with ph 5.8 water until the ph goes down? or can i use ,say, ph 4.5 water to flush it? I have flushed it a lot with ph5.8 water, but my run-off just wont budge. So what ive ended up doing is transplanting into fresh coco. Here are my plants. i know, i know,(damn newb) horrific how far behind they are for 40 day old plants! ive added a 400w hps, put in a 10 000btu ac to control temps, fed them with canna coco nutes and started buying dry ice to increase co2. any help would be appreciated
Your runoff sounds fine to me. You are aware that the coco is retaining cations from your solution, yes? This process will obviously result in a change in the pH of the solution because the solution is going to deposit some elements while removing others which are in excess. Think of the coco like a filter. What you are seeing with the pH in/out is what myself, and many others, see regularly. Do a slurry test to determine the accurate pH of your media as recommended by the dutch nutrient company you are using. Instructions can easily be found on their website. 5.8pH going in every time. Collect 30% as runoff. Not much else to it. Coco is extremely pH stable. Do not "high-low" your media with lower pH feedings thinking that the runoff is what is in the media. I have personally used a system that relies on organic acids which provide a misleading pH reading. Regularly I would use a 4.2pH solution in and get 6.4pH out. There were no issues with the system with regards to pH because the combination of weak organic acids and coco's self-buffering capabilities balance out. Not to say that anyone else should try this, but it worked fine for me, and taught me a few lessons about pH in coco. It really isn't something to be that concerned with. The yellow on your plants could very well be an iron deficiency as there is no iron contained in the Canna Nutrients system (yet this element is required at 5-7ppm for healthy growth, especially in a cation rich environment like coco). This is a BLARING issue with Canna Nutrients and is the reason (whether they know it or not) why Cal-Mag Plus works so well with their system. It isn't the Cal. It isn't the Mag. It is the "Plus" that makes a difference. Honestly, your grow room sounds like it has had its share of problems and, given the media of choice and the in/out, I do not think your problem is with pH.
Thanks for your input SCMC. i would appreciate it if you could help me diagnose my problem then. Will put pics up of the setup later today
treat coco coir like hydro.. water at 5.9 and don't pay attention to run off PH it is off. coco coir naturally likes to return to neutral. just be steady at 5.9 and you will be fine water every day.
Run off ph is not the most accurate in my opinion. Those rapid ph soil(ace) testers work better. Your idea of using ph 4.5 is the best choice to get a lower soil ph, then fine tune her in from their....
he's in coco and throwing even 3.9 ph at it won't budge for a 100 gals 5.8 5.9 don't read run off ph slurry will tell u whats up, and don't be surprized if that reading is alittle high too.
How much feed have you been giving them??what are your temp differences(between light and dark and how often are you watering??as for your PH probs,keep it between 5.6 and 6.0,ignore your runoff(once it's gone through who cares)have you used any Rhizotonic with these??if there 40 days old I'd be thinking that your roots haven't formed correctly,also with using a lower PH in,your gonna be locking something out,I've grown in coco using nothing but A+B,Rhizotonic,cannazyme and PK 13/14,if you follow the canna grow guide you can't go far wrong,I don't even use an EC meter,I have done but following the guide makes it redundant,hope things pick up for ya pal
You shouldnt give a damn. You feed the plant. It uses what it needs, and the medium lets go of what the plant doesnt need...this run off makes a new solution of nutirents (ions) with a new pH.
I know this is an old post but is it still the case that canna coco A/B doesn't contain iron, on the back of my bottles it states FE(chelated iron), but this is years later.....