Recirculating Canna Coco - Mg problems?

[DirtDoctor]

Hey guys, this is my first run with Canna Coco nutes, and I'm lookin for a little guidance

plants - Mr Nice (G13xHP) from clone (70 day strain)
medium - Royal Gold 100% coco (ph 6.5, EC=0.5 out of the bag)
Recirculating Top-Drip system using 1-gallon pots with a 5/8" coco mat underneath.
nutes - Canna Coco A&B, Cannazyme, Epsom
lights - 2K watts HPS
temps - 75F daytime, 65F nights
rez temps - cool (100 gallon Rez, underneath the table)
source water - EC 0.2 ([email protected])
watering 1x/day
current nutes - 8ml/gallon each, Canna A&B + [email protected] per gallon
ph steady @5.9-6.1
nutrient EC = 1.4 ([email protected])

The girls vegged about 10 days, and had roots growing into the coco mat before I flipped them.

They've been flowering (12:12) for about 5 days and are 12"-16" tall.

The first week I ran them at 500 ppms(0.7), then after about 6 days I bumped them up to 800ppms(0.7) because the girls were slightly yellowish - I attributed this to adapting to their new home and growing need for nutes.

Growth rates have been marvelous.

As they didn't green up enough for my tastes, I dumped the rez (to get rid of whatever I flushed out of the coco during the first week), and brewed up a new batch: 8mls/gallon each of Canna A&B (bringing my water from 130 to [email protected]) I then added 1/4 cup of Epsom salts (about 70 grams) to the 100 gallons of solution. The solution went from 930 to [email protected] (EC=1.42).

It seemed to me that 24 hours after watering with this mix, the yellowing was still progressing, so I added another 1/4C of Epsom, and then diluted the mixture back down to 960 ppms(0.7) with tap water.

Plants & roots are growing nicely enough, but it seems like the yellowing is continuing to progress.

Is this a mag deficiency?

Is my nute solution to strong or too weak?

Should I be aerating my rez?

pics @ Day 5 of Flowering:

 

[DirtDoctor]

thx for the reply, Cnna

I dropped the pH to 6.5, and flooded the table.

I'm going to foliar feed tonight with AN's Revive (1.5%N, 1%Fe, 1%Ca, 0.5%Mg, 0.5%Zn).

I'll definitely be using PK13-14, probably in low doses once the buds really start to set. I'll probably switch to AN's Overdrive in week 6 or 7.





I calculated the nute profile I've given em, with the additions of Epsom:

N 121
P 41
K 59
Mg 70
S 67
Ca 163

It's a little much Mg, but not too crazy out of whack I think

 

[rooted]

1.4 is light for a g-13 hybrid

ditch the epsom and get a bottle of botanicare sweet or technaflora sugardaddy, wave goodbye to your mag problems (advanced nutrients sweetleaf is NOT the same thing)

sweet and sugardaddy are both mag/sulfur supplements

 

[20kw dreams]

Yeah, looking at that profile you posted says to me your running a bit too low for how vigorous they look. Set the N to 200 or so with the other nutrients in the same proportions, and you should be in for a ride.

 

[Guest]

I have been under the impression that Canna does not endorse recirc with the coco specific nutes and their coco. I always ran it drain to waste (garden flowers) and never had a def. I believe that as it recircs the plants eat and cause an imballance in the mix.

 

[Kenny Lingus]

hmmm, I've never had mg troubles with canna, and my tapwater is way to soft for even sweetwater aquarium fish. EC 0,00 (It has no traceable cal or mag and I use canna coco at an ec of 1,2-1,6 for my strains. Maybe the bioboost and rhizotonic has some of it though)

 

[Guest]

i ran into ca/mag def when i tried canna coco nutes in a recirc. set up. i switched back to floranova, saved money and haven't had any probs at all. i use 1ks and co2, ec range from 2.2 to 2.4. the higher the light intensity and harder you push the plants the faster you'll find the limits of the nutes.

it wouldn't hurt to take readings from pot runoff to make sure it's where you think it is. looks like a simple increase in ec would do the trick.

 

[Kenny Lingus]

If you recirc with as little runn off as possible in 3-5 daily waterings and keep the coco good and wet all the time (and flush for a day with water before mixing new res you can get by just fine.) You should try to keep the EC stable and always dump the res when its only 5-15% left. I'd make up nutes to last for 7-10days, depending on stage of growth.) Of course rhizo and booster should help (rhizo being kelp/alga derived and bioboost being a bit molasses-like)

a teaspoon of epsom per 10litre should also do it I think.

Now when I think of it I see that it could be different for large plants, as I have merely grown clones that's been vegged for 2 weeks tops.

GL mate, and keep those plants blooming

 

[DirtDoctor]

Hey guys - just a quick update:

I increased the EC of my recirc solution, from about 1.2 to 1.4 then 1.6 as suggested, and I got nute burn

Oh well, no biggie, I doubled the amount of Epsom I was using, brought the ppms back down to about 1.2 and things started greening up again. (it probably helps that they're almost 3 wks into bloom and the initial stretch phase is over)


I'm not sure if the strain (Mr Nice aka G13xHP) is a total Mag whore, or if it's just from an excess of K+ in the coco that was blocking Mg+ uptake.... I'll flush the coco better in the next table I set up, and see if the issue comes up again




thanks for all the input y'all !!



Day 17 of 12/12:

 

[20kw dreams]

Lookin good.

There is no reason coco can't be used in recirc at all, I don't know what people are talking about. And you def shouldn't keep the coco wet, unless you are running your EC higher then you should.

I notice that just about every time I start out in coco I get a Mg def. I would say 80ppm should be enough though, as opposed to the 50 or so I think most nutes start out with. That's adding 30ml/25 gals or so.

Your plants are looking good though, so nice one:tup:

 

[seaweed]

You need to incress your e.c. You may need to simple incress your watering cycles. I am not sure with canna but I use cutting edge this way.
Cutting edge with botanica care cal mag 1200 ppm
6 waterings a day at 13 min a cycle.
RG has more air in it than other coirs. I tried one to 6 waterings a day in 5 inch pots . Plants like to take off slow and move up to 6 waterings within the first week to 10 days of veg. The 100 % RG looks just as good as the perlite coir blend.