Adapting Canna Coco A+B Formulation for 30% perlite 70% coco and RO water

I've been growing in coco with canna nutrients and I'm considering making my own and making changes to my nutrient profile to better match my setup. My setup varies off the normal coco setup in that I use RO water and a 30% perlite 70% coco mix.


I've considered rockwool slabs or clean perlite in the past for nutrient solution and substrate predictability, but I like that coco still retains some soil like qualities in that it binds some nutrients for a smoother delivery over the long term, and as such is more forgiving. Maybe one day i'll make the switch.


I like the canna coco range as its high in NPK and balanced well with the Ca (near 4:5 Ca:N) something that cant be achieved without running to waste and a drip system.


I'm considering formulating my own and tweaking the formula for lower Ca, more like 4.2% (from 4.5%) and upping the Mg to 1.6% (from 1.2%).


The idea is that using the 4:5 Ca:N ratio as a baseline, the reduced coco in my coco-perlite mix means lower Ca binding and thus more Ca available to limit the uptake of everything else, thus lower Ca will boost uptake. The idea with upping the Mg is that it is off the typical 1:2 Mg:Ca ratio and by upping it I'll avoid the need for Mg additives while synergising N and P uptake during veg. I also compensate for the fact that coco will bind some of the Mg. Mg can block K which can be problematic during flower, but I suspect that adding mono-potassium phosphate to the mix will be beneficial. During flower I will drop Mg to 1.2% to prevent higher K from synergising causing Mg burn.

Perhaps i should make a A+B for veg and A+B for flower formula. Both Veg and Bloom, with a Ca of 4.2% and then 1.6% Mg for Veg and then drop to 1.2% Mg for flower with Mono-potassium phosphate.


What you think, am I about to head into problems or is the reasoning sound?

Seems to me that all you need to do is add some calmag to make up for that deficit (normally provided by tap water). Otherwise, the Canna nutes should be fine.
JD

I have gone both ways, tap and ro and if you use ro, take the ppm up to around 200-230 with Cal-Mag and consider that your base line and then go with the rest of the nutes as you stated. I have seen no issues in my setup and I am in pure coco this round, no perlite.

Peace and Great Grows

Asmallvoice

Unless you are using "canna coco" with the canna fert, It's always a really good idea NOT to trust the manufacture has properly buffered the product. I always buffer all coco I use. Doesn't matter if it's pre-buffered, plus coco can range anywhere from 5.0-6.5 And if your running dominant coco and pre-buffered at 6.5-----good luck. Optimal PH for coco is 5.8 This is very important to have a high quality coco and get it from a trusted seller/shop/manufacture. If you are using coco as a amendment to your organic soiless mix, then 6.5 is great.

Get some ca/mg+fe, and use RODI H20, mix up a buffer solution that reads 3.0EC and 5.8PH. If you need to PH down, I would use phospheric acid as P is not as readily leached from media's like other elements. This will help PH stability and work with the ca/mg buffer.
Soak for 12hrs----drain-----re-soak with PH 5.8 RODI @0EC for 12hrs----drain and take reading.

Few coco buff's are aware that measurement of EC/PPM/PH is inaccurate when results are found in the run-off. The proper way to determine accurate values is to take a media sample.
A 1:5 ratio of media to RODI H20. Sooooooo, 1 cup of coco (I like to take core samples with beveled edge pipe) and 5 cups of water. Put it in a 2000ml jar with lid and shake the shit out of it for 2-3min, then let it sit for 30min. Come back and remove solution from bottom sediment (I pour thru a coffee filter). Now this solution is what you test.

ASMALLVOICE said:

I have gone both ways, tap and ro and if you use ro, take the ppm up to around 200-230 with Cal-Mag and consider that your base line and then go with the rest of the nutes as you stated. I have seen no issues in my setup and I am in pure coco this round, no perlite.

Peace and Great Grows

Asmallvoice

Click to expand...

I read and admired you journal this morning. Nice job!! Last time you were 70/30 I believe. Now straight coco, hmmmmmmmm, I would monitor moisture levels with a digital probe first before comitting to an automated drip. without perlite she will hold lots of water and you risk rot.

tikitoker said:

I read and admired you journal this morning. Nice job!! Last time you were 70/30 I believe. Now straight coco, hmmmmmmmm, I would monitor moisture levels with a digital probe first before comitting to an automated drip. without perlite she will hold lots of water and you risk rot.

Click to expand...

I thought the same, till I learned a bit more about how water's specific gravity works in a potted plant, I cannot remember where the info is on here, but water does not react in a pot like most think it does. I water 4 times a day for 30 seconds and 1 time a week for 1.5 minutes (small weekly flush) I have immense root systems and stalks that are over 1" in diameter on a 28" tall plant.
My pots have a small gap under them and they drain rapidly ( 3 gallon plastic bag type)and I cut many more holes in the pot than came from the factory, top to bottom.
I am flushing now and will harvest right after the holidays. In my experience, the pots with perlite mixed in, held just a much, if not more water than straight canna coco.
I use 22 gallons a week for 4 plants ( 18 actual used, 4 just for pump pickup)

Peace and Great Grows

Asmallvoice

ASMALLVOICE said:

I thought the same, till I learned a bit more about how water's specific gravity works in a potted plant, I cannot remember where the info is on here, but water does not react in a pot like most think it does. I water 4 times a day for 30 seconds and 1 time a week for 1.5 minutes (small weekly flush) I have immense root systems and stalks that are over 1" in diameter on a 28" tall plant.
My pots have a small gap under them and they drain rapidly ( 3 gallon plastic bag type)and I cut many more holes in the pot than came from the factory, top to bottom.
I am flushing now and will harvest right after the holidays. In my experience, the pots with perlite mixed in, held just a much, if not more water than straight canna coco.
I use 22 gallons a week for 4 plants ( 18 actual used, 4 just for pump pickup)

Peace and Great Grows

Asmallvoice

Click to expand...

I think the whole idea with coco is the frequent feedings. That's the key to a bumper crop. Coco has a low CEC whereas peat has h high CEC. (caution exchange capacity) this is the measurement in which a media has the ability to hold nutrients and release them gradually. With frequent feeding/irrigation, it's very important to provide extra 02. So yes you will still crop out with less feedings, but now you risk salt. You are flushing every week 1.5 min. If you were in a better ratio suited for heavy/frequent irrigations, you would have to flush 1x/week. You could set each feeding to be 10sec longer and that would flush and replace, then if your recirculating, adjust rez values. Dump rez every week.

But I like your style and will be there for the grow.