StudentGreen said:

Hey guys, wondering if I can get some help on using ro water
I am growing cannabis in only coco substrate using the canna coco line of nutrients and great white microhizae.
I have soft water where I am but thought I’d invest in an ro system to bring my ec close to 0 so I know exactly what I’m giving my plants and I’m starting off clean without things like chlorine.
Are there any other substances like iron or aluminium which is in my tap water needed to be added back in or is my canna line of nutrients going to be sufficient.

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i’m sure you’ll get the answer soon enough but to me tap water is better than ro water for plants,.

GNick55 said:

i’m sure you’ll get the answer soon enough but to me tap water is better than ro water for plants,.

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Why is that?

StudentGreen said:

Why is that?

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ro removes all minerals so than you have to replace after filtration to feed the plants,.
and it’s counterproductive though you say you have soft water so that means possibly high in salts which could cause issues with some plants,. marijuana for the most part can easily handle water straight out of the tap without sitting out,.

i’m not telling you what to do,. it was just an opinion and to bump your thread as i’ve never grown with coco and it’s different than soilless/organic,..
you should get some replies soon

GNick55 said:

ro removes all minerals so than you have to replace after filtration to feed the plants,.
and it’s counterproductive though you say you have soft water so that means possibly high in salts which could cause issues with some plants,. marijuana for the most part can easily handle water straight out of the tap without sitting out,.

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Yh that does make sense with it being counterproductive, I just thought having a clean slate to start with may be better than having little amounts of substances that I don’t know exactly how much there is of in ppms so at least with ro, I know exactly what goes in my res and I’m not giving my plants anything that’s not good like the chlorine and fluoride etc. pretty sure that stuff ain’t any good for the microbes… thanks for the support though, didn’t really expect anyone to reply to me but threw it out there anyway lol

StudentGreen said:

Yh that does make sense with it being counterproductive, I just thought having a clean slate to start with may be better than having little amounts of substances that I don’t know exactly how much there is of in ppms so at least with ro, I know exactly what goes in my res and I’m not giving my plants anything that’s not good like the chlorine and fluoride etc. pretty sure that stuff ain’t any good for the microbes… thanks for the support though, didn’t really expect anyone to reply to me but threw it out there anyway lol

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@Trash_2002
i think knows about growing in coco etc,,
he should reply when he’s on,..

What concerns you about your water? Did you got it tested and its high in sodium or have crazy high alkalinity? Are you having problems?

If not no need for RO at all.

Sometimes RO can be a problem too, in certain situations it can struggle to keep ph buffered, it should be rebuferred before use with calmag or something like potassium silicate or calcium carbonate etc.

RO should only be used in regions where water is lab tested bad imho.

Cheers.

RO is the correct path in your "soft water" situation. Canna Coco is pre-buffered so you shouldn't have any CEC issues. In Coco or any Soilless Media a good Combo Meter that reads tds/ec/ppm/pH is necessary, (the 14.00 amazon units are junk), In Hydro we need accurate readings on what goes in and what's coming out (run-off testing) As Coco and RO both are inert and contain nothing, it is up to the Gardener to supply atomic elements the Plants need, the Canna Coco Nutrient Line should contain everything Your Plants need, (see the guaranteed analysis). follow the directions on the Bottles

You didn't mention what you are growing?, If growing Day-Neutral start out at 50% dosages. Many Auto's will not tolerate full dosages. (maybe 75% dosages mid flower. (strain dependent)
If Growing Photoperiods start at about 75% dosages, and raising incrementally to full recommended dosage. (checking for tip burn)

All nutrient companies want you using full dosages...I wonder why? lol

In DWC I am way lower than recommended Dosages. In Coco Im about 75% of full dose. (with Day-Neutral about 60% of full dose)
If they are drinking a lot in high heat with high transpiration rates, they also need less nutrient.

When asking for advice try to give more info- Type/Species/Strain/Breeder, Size of Pots, Lighting/Grow Space Setup, environmental controls/testing equipment.

Ive been in Hydro for many years, with my coco setups Ive learned to build my coco 55/45 Coco/ #3 Perlite, (I use #4 perlite if I can find it at 60/40) fast draining/fast drying, they will grow like beasts, and its easier/faster to correct imbalances. good luck my'dude!

First of all, thanks for the support lads, really didn’t expect people to actually reply. I’m quite overwhelmed lol.

Furthermore, I probably should have provided a little more info on my setup so my bad but here goes.

I’m growing an India dominant strain in stardawg in 11 litre pots, I have 16 pots in 4x4ft space. About 160 plants in total. Pots are in elevated 4x4 trays running a drain to waste system. Medium is just coco professional plus, bought perlite but didn’t use it… using canna coco nutrient line for the first time.

Lighting is 600w hps, with dual spectrum bulbs,
Will be changing over to led when I have the money.

Running a sealed room with no ins and outs. Using bottled co2 enrichment, at the moment set on around 8-900ppm
Using humidifiers, dehumidifier and air conditioning to control temps and humidity following the vpd chart for veg growth.
At the moment temp is at 25 degrees c and humidity at 60 percent.

Using blue lab truncheon meter and blue lab ph pen.

Using tap water which comes out at 0.2 ec and 7.3 ph.



I’ll post some pics below of my set up and my water checks for my area too.

So I’ve been running into quite a few problems since i started this crop.
First I ran into what I believe was a calcium deficiency as I wasn’t supplementing calmag, grow store guy said you won’t need it pal so I took his word for some reason lol. Started getting yellow spots with rusty outer lining and plants started to look yellowish.

Then had a problem with my ac which was my fault tbf but came into a sealed room which was 37 dc…. That happened over night so definitely caused some stress there too.

Then to rectify the calcium I brought my ec to 0.4 with calmag before adding nutrients to rectify the deficiency but I think I overwatered my plants so they all started to droop heavily.
Whilst they were drooping and not looking good at all, I decided to transplant into the 11 litre pots as some of roots were starting to get rootbound whilst they were in the 1.5 litre pots.
When transplanted I let the plants dry out a little and didn’t water for a couple days, just watered them yesterday and could say they look a little better, sprayed them twice last night whilst lights were off with rhizotonic from canna and they look something like this….. also should mention I was running the lights 24 hours so this probably added to the stress but below are some pics of the setup and water data. Forgive me it’s not too clean of a room but just broke my foot in football 2 days ago.

Lastly, I made my nutes 2 days ago and in about 48 hours my ph in my reservoir has risen from 5.8 to 6.4, one of the reasons why I thought of getting an ro system and using potassium silicate as a ph up then bringing it back down with ph down to get the buffer I need, read a forum about this yesterday. Plus potassium silicate would give my plants silica which also helps too right.

Ah forgot to mention and sorry this is definitely the last thing but just bought a soil ph tester and my coco oh coming at 7.0 ph…. Is this really bad?

Your coco looks really dry, and it likes to stay moist at the very least. Being too dry is maybe your biggest problem. It's a hydro medium, and it's really hard to overwater in coco. First thing I'd do is give them a thorough drenching, maybe even flush them with 3x water ph'd to 5.8 - 6.0 to pot size. Then back to at least daily feedings. When coco dries out, it messes with the CEC and ph of your coco and you start seeing deficiencies present like you're seeing now with the yellowing.

Probably the best thread I've seen for how and when to water in coco.

Totally get what you’re saying and just read that link you posted, however I feel there’s always 2 different opinions circulating regarding the dry backs.
Some like you say keep the coco highly saturated and some say keep it fairly dry.
Well I’m using cannas coco professional plus and canna themselves have a video on YouTube explaining how to water the coco and they mention keeping the coco between 30 and 50 percent moisture content, so that there is enough nutrients in the coco but also a lot more o2 for the roots compared to having more moisture and less o2 availability.
Also recently watched a video of a chap from advanced nutrients on a YouTube video explaining the importance of having a large dry back especially in veg when transplanted. Advising to fully saturate at the first feeding and then to wait for the coco to be at around 30 percent moisture content to then feed again.
I’ll link the videos below for you to watch

This the canna guy


The advanced nutrient guy

StudentGreen said:

Totally get what you’re saying and just read that link you posted, however I feel there’s always 2 different opinions circulating regarding the dry backs.
Some like you say keep the coco highly saturated and some say keep it fairly dry.
Well I’m using cannas coco professional plus and canna themselves have a video on YouTube explaining how to water the coco and they mention keeping the coco between 30 and 50 percent moisture content, so that there is enough nutrients in the coco but also a lot more o2 for the roots compared to having more moisture and less o2 availability.
Also recently watched a video of a chap from advanced nutrients on a YouTube video explaining the importance of having a large dry back especially in veg when transplanted. Advising to fully saturate at the first feeding and then to wait for the coco to be at around 30 percent moisture content to then feed again.
I’ll link the videos below for you to watch

This the canna guy


The advanced nutrient guy

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You water source is pretty good , I would be concerned if ph was 8+ and EC 400+

My only pointer is that I would drop the calmag and just use magnesium sulfate in your water
32:2 Ca:Mg in your water so using only mag sulfate you get a better calmag ratio before adding the nutrients.

From the pictures I see heat stress, and nutrient lockout, maybe media drying back too much? Too high EC together with too much heat/transpiration? Watering frequency not the best?

You want to fully saturate your coco and that's your WC base line, the dry back will be around 10% less than that base WC in veg, and around 20% less than that base WC in flower. In theory, you should experiment.

Here are some good guide lines for your crop steering since I get you're going this path:

If hand watering just go by pot weight if it's 30-50% lighter pot weight in coco water again. With at least 15% runoff.
Cheers

Trash_2002 said:

You water source is pretty good , I would be concerned if ph was 8+ and EC 400+

My only pointer is that I would drop the calmag and just use magnesium sulfate in your water
32:2 Ca:Mg in your water so using only mag sulfate you get a better calmag ratio before adding the nutrients.

From the pictures I see heat stress, and nutrient lockout, maybe media drying back too much? Too high EC together with too much heat/transpiration? Watering frequency not the best?

You want to fully saturate your coco and that's your WC base line, the dry back will be around 10% less than that base WC in veg, and around 20% less than that base WC in flower. In theory, you should experiment.

Here are some good guide lines for your crop steering since I get you're going this path:

Crop Steering

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So is what your saying the 32 ca is enough calcium for my plants and don’t need any more supplementation?
If I use the mag sulfate, at what ratio should I be diluting it?

Yh maybe nutrient lockout, I put the soil tester probe in the coco and ph showing 7.0 so not sure if that’s the reason for locking out or maybe it’s because my ppms are too high. I am feeding at around 800 ppm, maybe I should cut it down a little.
Moisture content not been too dry so don’t think it’s that.
I’ll definitely be looking a lot more into crop steering too thank you

StudentGreen said:

So is what your saying the 32 ca is enough calcium for my plants and don’t need any more supplementation?
If I use the mag sulfate, at what ratio should I be diluting it?

Yh maybe nutrient lockout, I put the soil tester probe in the coco and ph showing 7.0 so not sure if that’s the reason for locking out or maybe it’s because my ppms are too high. I am feeding at around 800 ppm, maybe I should cut it down a little.
Moisture content not been too dry so don’t think it’s that.
I’ll definitely be looking a lot more into crop steering too thank you

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Just up the base 200uS to 400uS with magnesium sulfate before adding nutrients,

EC 1600uS for that size plants is too much, try something like EC 1000uS is plenty for now

Not sure if I would trust that soil ph probe tho.

GNick55 said:

ro removes all minerals so than you have to replace after filtration to feed the plants,.
and it’s counterproductive though you say you have soft water so that means possibly high in salts which could cause issues with some plants,. marijuana for the most part can easily handle water straight out of the tap without sitting out,.

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1 million percent agree. I’d use tap if my water quality was up to par as the well as most states in US and Canada. But where I’m at, if I can’t drink it neither can my plants. I’d love to be able to get affordable water without having to supplement calmag in the mix.

Choppr said:

All nutrient companies want you using full dosages...I wonder why? lol

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This seems incredibly stupid to me, in the short run they sell more but if someone has bad results they are more likely not continue to use & lose a customer to someone who "might" be more honest in dosing.

Glassdub said:

This seems incredibly stupid to me, in the short run they sell more but if someone has bad results they are more likely not continue to use & lose a customer to someone who "might" be more honest in dosing.

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I think all nutrient companies do this, probably a mutual thing for them so they all make money

StudentGreen said:

I think all nutrient companies do this, probably a mutual thing for them so they all make money

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Yeah they do but it's universally stupid.