Bicarbonates in coco...please give your input

[GDK]

Hey guys.
Im on my first grow with coco and im experiencing trouble. I read up on coco and the do´s and dont´s, and went ahead and bought a RO unit. Was told by a reputable coco grower at the site to mix tap and RO to ec .3.
I did and followed Cannas directions and i was amazed at how the plants grew. Soon i had to repot and i was so amazed by the growth that i might have gotten carried away and fed a little too much (ec 1.6). The girls started growing very dark and with mutated features similar to those of revegging. So i flushed with ½ strength nutes and fed lightly for the following days. Thats when the problems began.
I had been feeding at ph 5.7-6.2 and ec 1.2( except for a cpl of 1.6 waterings)
The girls started looking pale and with spots on the leaves accompanied by purple stems and petioles, and a droopy look to em.
I then started chatting with a very knowledgeable member who took a view at my water analysis, and concluded that i had some serious amounts of hydrogen carbonate in my tap. Per his advice i have been watering with straight RO and nutes, ph´d to as low as 2.0 at one point to wash out the bicarbonates. I have never gotten runoff lower than 5.9 even with 2.0 goin in. Currently i am watering with ec 1.8 and ph 3.5 and my runoff averages 6.2 and ec as low as 0.5. Im also beginning to think the plants are rootbound and im thinking about transplanting into 20 liter buckets to give them some more room. But like my "teacher" tells me, the bicarbs seem to be stuck in the rootmass...so any ideas?
Heres a few crappy phone pics of the situation...each pic is a different plant.

Heres my water analysis:

Tell me whatcha think?

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[GDK]

Really..? No one..?

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[SeaMaiden]

I forget how to convert mg/l into ppm or other conversions I am familiar with. And the terminology and notations used are unfamiliar to me. However, I'm looking at the nitrogenous content (NH4, NO2 & NO3) and I find myself wondering what those values are in terms of ppm and, this is key, how they might be changing the nutrient profile. Mostly, the way your plants look I would have suggested an issue with pH.

Are you using runoff only to measure the feed/media parameters? If so, I suggest using a different, and IMO better method -- a media test. You will need a sample or group of samples (take media from however many pots you're using) taken from different levels of the pot. This isn't difficult, you can either flip the plants out of the pots or you can dig down carefully to get them.

Now you need a sufficient amount of clean, low-to-no EC water, if that RO machine is working properly that's what you should use. Get the parameters of the water written down, you need to know pH and EC at least. Now you mix enough water into the media samples to make a very wet slurry, and you're going to mix it well, then let it sit a minimum of 7 minutes. I have found no significant changes occur beyond 10 minutes, so I let it sit for 10 minutes.

Strain off the media (you don't actually have to do this, but I'm anal retentive that way) and test the parameters of the water that remains. This will give a good idea of how much the pH is shifting, whether or not there's a build-up of salts, much more accurately and reliably than the runoff method.

 

[GDK]

I forget how to convert mg/l into ppm or other conversions I am familiar with.. Mostly, the way your plants look I would have suggested an issue with pH.

Mg/l is the same as ppm. About the ph. The guy whos trying to help me told me that its the hydrogen carbonate that has accumulated in the pots, making the ph rise constantly. He has also suggested that i let them dry out completely between waterings, which i thougt was a big nono i coco. Tried it, but it still seems the plants do better when they are kept wet. Actually they all perked up a bit from yesterday. Ill definately try out the slurry to achieve a more accurate reading of the ph. But isnt it safe to say that something is off when i run 2.0 water thru and it comes out around 6? And the low runoff ec as well?
Im transplanting this week as im gettin more and more certain that they are rootbound as well...the surface coco is all covered in roots..

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[ScrubNinja]

I've never used it, but there's a product called something like Drip Clean which would seem like a good thing to flush everything out.

 

[Green lung]

Overwatering. no cal mag, ph issues


causing ph problems, soggy coco


and def add cal mag to youre ro water, ro water with no cal mag the PH swings very easily.


I bet you look at your root system it probably is very week and far from rootbound.




Coco can be more easily overwatered when plants are young and/or after they are transplanted into larger pot of coco, it takes time for the roots to explore the new coco and build a large root system to except all of the water.

 

[Hydro-Soil]

and def add cal mag to youre ro water, ro water with no cal mag the PH swings very easily.

pH swing is nute dependent. Cal/mag is not a cure all and really isn't wanted in most situations. Highly overused product.

Adding nutes to your water will do the same thing as Cal/Mag for the pH... this is why you pH after you add your nutes. Still have pH issues? Either there's an issue with your medium or plants... or you need to change nutes or your pH up/down.

Stay Safe!

 

[GDK]

So are you guys totally dismissing the amount of bicarbonates in my tap, and the possible fact that it might be the bicarbs fucking shit up?
I always ph after mixing nutes, and use nitric acid for ph down. Thing is that when i used to mix tap and ro, the ph would rise in the small res

"either theres an issue with your medium or plants.." Thats what im gettin at. I want to know how to get rid of these fucking bicarbs in my medium. The member thats directing me via pm told me that if i tranplant into bigger pots, i should soak the new coco in ph 5.0 with 30% tap 70% RO to buffer the new coco. That means that he thinks the only way is for me to water with 3.0-3.5 ph for the rest of these plants lives....i want to get rid of whatever is causing this in the media, and be able to continue with normal ph/ec feedings..

Stay Safe

 

[SeaMaiden]

I'm not, but like I think I said before, many of the terms are unknown to me. Also, from a chemistry standpoint I don't know enough on the subject to speak to it. What I do understand about them is that they may increase alkalinity of water, which would mean the pH is 'buffered' upwards and will resist pH shift.

But, to my mind the hydrogencarbonate isn't the only factor to be considered. Everything that might contribute to the total available nutrient profile, that might affect uptake or utilization needs to be considered. As I recall, without going back and rereading, aren't you using a nutrient line that's designed to be used with plain tapwater? And wasn't it when you switched that troubles began? Whatever the cause, maybe it's better to go back to what worked, then work your way backwards to see what might have gone wrong. Sorry I can't offer more help.

 

[Green lung]

It started after you repoted or got worse?


Are you watering to runoff?

Are your pots heavy?







You could just take your plants into the shower, mix up a 5 gallon bucket of RO water cal/mag and nutes with a ph of 5.6-6.0 and flush the hell out of your plants and check the runoff Ph until you get runoff ph of 5.6-6.0.

I recently did this after my PH pen was wrong and I was watering with a ph of like 7 for a day or two, and saw problems in plants and check recalibrated my PH pen.



/

 

[GDK]

I bet you look at your root system it probably is very week and far from rootbound.

Just flipped one of the gurls out of the pot and i have never seen so many pearly white thick healthy roots in a 12 liter pot before..i say its time to transplant?

As I recall, without going back and rereading, aren't you using a nutrient line that's designed to be used with plain tapwater? And wasn't it when you switched that troubles began? Whatever the cause, maybe it's better to go back to what worked, then work your way backwards to see what might have gone wrong. Sorry I can't offer more help.

Im using Canna Coco A+B with the recommended dosage. I believe you are right about them being designed for tap, but my tap has an starting ec of .9, which i was told was off the charts, and needed diluting to achieve superior results...but i have actually been thinking about it more and more these last cpl of days...maybe i should try to use straight tap and just ph it to like 5.5 and see what happens...im just scared because even at 2.0 goin in i still get 5.9 goin out...so i cant imagine what happens if i feed at 5.5..
Actually i never switched. Only thing i did was use less tapwater in my mix to try to fix the problem. Went from 25% tap to straight RO, and these last 3 waterings i have been using rainwater, which seems to be just as good. So no..the troubles began before goin straight RO. And dont be sorry..your time and advice is greatly appreciated girl..

It started after you repoted or got worse?

Are you watering to runoff?

Are your pots heavy?

You could just take your plants into the shower, mix up a 5 gallon bucket of RO water cal/mag and nutes with a ph of 5.6-6.0 and flush the hell out of your plants and check the runoff Ph until you get runoff ph of 5.6-6.0./

Didnt get worse right after repotting..later on it did, which is partly the reason im thinking they need more room for their feet. Pots have been kept wet, dried out completely..tried everything in between...
I have tried to flush em several times, but i dont think i used enough water...i guess i should use at least 5 gallons of low strength feed solution for these 12 liter pots..

I watered with rainwater ph´d to 3.5 and ec´d to 1.6 today with a good amount of runoff. Used AtaClean(like dripclean) too. Most of the plants had runoff ec from 1.0 to 1.5 with a single one only hitting 0.5. Their ph in the runoff ranged from 6.2-6.5..pretty crazy eh? They are showing slight improvements tho..but nowhere near where they should be...and them shits is gettin big as fuck..im thinking im running outta room soon and might have to discard a few of them to make room for the rest....cant believe that it was so easy at first, and now its a fucking battle..

Stay Safe

 

[ChaosCatalunya]

..."Per his advice i have been watering with straight RO and nutes, ph´d to as low as 2.0 at one point to wash out the bicarbonates. I have never gotten runoff lower than 5.9 even with 2.0 goin in. Currently i am watering with ec 1.8 and ph 3.5 and my runoff averages 6.2 and ec as low as 0.5. "

This sounds bad to me.


At first you did well, but then overfertilised, however I think you have gone way off course with the flushing, keep it in pH 5.8-6, but lower the nutes. Ignore the runoff readings, look at your plants.

 

[GDK]

This sounds bad to me.


At first you did well, but then overfertilised, however I think you have gone way off course with the flushing, keep it in pH 5.8-6, but lower the nutes. Ignore the runoff readings, look at your plants.

You know what...i have been thinking this all along. So do you suggest i simply revert to my original feeding schedule with 25% tap, 75% RO ph 5.8 ec 1.2? No flush, no nothing...well maybe a transplant...we are talking big ass bushes on their 9th week of veg..

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[volhead]

I am running canna coco......i just de chlor my tap water and add a little bit of cal mag never any problems.....i would stay away from all this mixing tap and ro water and crazy low ph.....i would flush with 1/4 strength nutes around ten gallons of water per those 3 gal pots. I would also just use RO or Dechlor never use tap its got all that chlorine that will kill any enzymes or beneficials you have in root mass. after you flush give them a little bit of a normal strength nutes. Those runoff test your getting really dont say much except for the very first bit of soultion that comes off. Intial run off is where you get your info from. After that your just getting a diluted reading of what your putting in. But im with chaos look at the plants they will tell you. make sure you ph and ppm pens are calibrated. o yea in coco with canna you really dont need a RO your just wasting water. I would just run a De chlor there cheap and dont waste any water and just plug in your values to the canna website calculator. That nute calculator is handy when gauging what to do with the hardness of your water. good luck

 

[mpd]

I find that SM-90 will cure most of the problems you have. Flush the damn plants and then make up a solution with SM-90 and have at it. The leaves look like you have overwatered the plant to these tired eyes.

 

[dramamine]

What a lot of random advice you're getting for your high alkalinity problem.........overwatering, overferting, SM-90 (???)etc. etc.

Your friend was right about your tap water. It's high hydrogen carbonate content is giving you high alkalinity in the rootzone, meaning your ph level will climb. You've seen the results of this already. Testing runoff ph isn't technically sound, but if it's rising that much from what you input, it's pretty clear where the problem lies.

When you know for a fact that your media ph is way off, it makes no sense to attempt a bunch of other solutions. It will only lead to more trouble, or wasted money at best. If I were you, I would transplant them right away, then go back to feeding at around 1.2 EC. The smaller the pot size, the faster and more severe the symptoms of a problem. Transplant, feed (using RO, no tap) to lots of runoff and I'll bet your problems go away quickly.

Also, Canna is made to be used with RO water, as stated on the container.

 

[GDK]

What a lot of random advice you're getting for your high alkalinity problem.........overwatering, overferting, SM-90 (???)etc. etc.

Your friend was right about your tap water. It's high hydrogen carbonate content is giving you high alkalinity in the rootzone, meaning your ph level will climb. You've seen the results of this already. Testing runoff ph isn't technically sound, but if it's rising that much from what you input, it's pretty clear where the problem lies.

When you know for a fact that your media ph is way off, it makes no sense to attempt a bunch of other solutions. It will only lead to more trouble, or wasted money at best. If I were you, I would transplant them right away, then go back to feeding at around 1.2 EC. The smaller the pot size, the faster and more severe the symptoms of a problem. Transplant, feed (using RO, no tap) to lots of runoff and I'll bet your problems go away quickly.

Also, Canna is made to be used with RO water, as stated on the container.

Boom....thanks man...thats the thing i wanted to know about...the fucking bicarbs. Theyll be transplanted to 5 gallons tomorrow. But are you agreeing that its impossible to wash out the hydrogen carbonate that has already accumulated? My friend is telling me to soak the new coco in 5.0 ph / 1.8 ec with 30% tap/70% RO to allign the old and new coco. He says that if i dont, i will have a center rootzone with a crazy climbing ph that needs the low ph feed, and a outer zone which will react negatively to the low ph feeding...
Im leaning towards yours and Chaos´advice to just transplant and carry on with a regular nute/ec schedule..

Stay Safe

 

[dramamine]

I would lean more toward flushing them very well at a low ph before you transplant, lots and lots of runoff. Probably you shouldn't use 30% tap water, since that's the root of the ph problem. A small amount of alkalinity is a good thing...it keeps your ph from dropping, but I would just use RO for feeding, at least until the issues go away. You said your roots are nice and healthy, so I would feed to plenty of runoff for the near future. If you see them getting hungry, just bump up the EC slowly.
I don't know how hard it is to flush the bicarbs, but after transplant the plants will begin to tell you how they are doing. One of the great benefits of coco is that you can flush heavily without suffocating your roots. It allows you to get past problems like this very efficiently. "Overwatering" in coco usually only happens as a symptom of poor drainage.

 

[ChaosCatalunya]

You know what...i have been thinking this all along. So do you suggest i simply revert to my original feeding schedule with 25% tap, 75% RO ph 5.8 ec 1.2? No flush, no nothing...well maybe a transplant...we are talking big ass bushes on their 9th week of veg..

Stay Safe

Exactly GDK, just use a normal pH, lower the nutes, COCO is pretty hard to screw up, and to date, just using KISS drain to waste, not going above 2.3 ml/L feed [canna] and pH always 5.8 to 6, zero problems for myself or any friends.

This is with my high pH well water, but also works with friends crappy town water, never used a drop of RO, perfect crops.

One buddy on the coast had some issues, poss crappy Chlorinated water, so he lets it stand 24h as a precaution, now has no problems.

Otherwise, I think there may be an issue with Temps and coco, I think coco goes out of range before soil grown plants when it gets too cold, maybe the medium's high water content gives more efficient thermal conduction. Easy to fix with a heater, but it can become an issue at this time of year above the equator.

"Also, Canna is made to be used with RO water, as stated on the container"

I have never seen this, looked into RO a lot after seeing so many people online talking about it, so I ended up talking to Canna people and Mr General Hydroponics about it, face to face, and got the same answer "we develop our nutes for plain tapwater, including all the carbonates that buffer it and keep it stable. People who remove them have to put in [expensive bottled] cal mag to replace the cal and mag they have removed and then they have problems with yo-yoing pH, they may even need more additives to cure.

 

[Herborizer]

My Canna does not say use RO water. I mix RO + tap water to reach 120ppm, then I add my nutes. Zero issues here.