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Buffering coco question!! HELP

C

Coco_nuts

Active member
Hi all

I have been having some calcium issues. Just harvested and will be up potting the veg plants and moving them into the flower room tomorrow.

I have been using GH 6/9 in 100% coco.

Ive been pre treating the coco with dolomite lime (2 tblspns per gal) but still get cal def in late flowering. (basically i hydrate the coco bricks with a 1/2 strength nutrient solution and add dolo lime).

I found this:

Coco Substrate Buffer

(Used for preparing non-buffered coco substrates such as compressed coco blocks)

Calcium Nitrate 290 g/l
Magnesium Nitrate 280 g/l
Magnesium Sulphate 10 g/l
Ferric EDTA 2 g/l

Make 1L by beginning with 500ml of RO (demineralised) water. Add ingredients one at a time, dissolving each ingredient before adding the next. When all ingredients have been added, top up to 1000ml (1L) with RO water.

What I recommend you do is hydrate the coir blocks in mains (tap) water. That is, fill a bucket or tub with mains water. Measure the EC of the mains water before adding the compressed coir block/s. Let’s say it’s EC 1.0 for arguments sake. Add the compressed coir block and allow it to expand. Stir the water and coco substrate around and then measure the EC again. You’ll no doubt find the EC is now much higher. OK, now run mains water through the coir (you may find a bucket with holes and mesh at the base helps here). Run the mains water through (flush) the coir until the water that has passed through the coir (runoff) is no more than EC 1.0 - 1.2. I.e. Original mains water EC ideally matches that of the runoff.

Now fill up a bucket with demineralised (RO) water and dilute the buffer concentrate to 1.4 EC (700ppm). Place the hydrated/expanded and water flushed coir into the diluted buffer solution and leave to soak for at least one hour.

After one hour or more, take out the now buffered coir and squeeze out the excess fluids so the coco substrate is not saturated/water logged. You may find drying it in the sun for a while helps. .

Ready to go – you now have a high quality buffered coir product at a fraction of the cost that you would pay for similar products through stores. I’d also recommend that you mix the coir with perlite. 60% coir to 40% perlite when using it as a run –to-waste medium.
Click to expand...

Now i have a ph pen and no ec pen so im kinda at a loss. Is there a easy way to buffer with calcium nitrate ie put x grams of calcium nitrate into 5 litres and add coco brick (i use the bricks)?

Im thinking of changing my mix to 33% coco, 33% perlite and 33% vermiculite or 60 coco and 40% perlite to downplay the coco cal problem. Would this mean i would have to use a different recipe? GH 6/9 is specifically for coco so i dont know.

Thanks for any help!

Regards
CN
 
pinecone

pinecone

Sativa Tamer
Veteran
Try using gypsum instead of DM. The advantage of gypsum is that it won't raise the pH as it breaks down. The other thing you might try is top-dressing with some earthworm castings. Earthworm castings are rich in Ca.

Pine
 
MIway

MIway

Registered User
Veteran
I believe preflushing the coir goes a long way in preventing problems, but that it is really balancing all cations (positively charged molecules), not just the Ca... I've found the K is just as important.

The recommendation you cited isn't a bad one, but if you wanted to simplify it...

Hydrate your coir in tap & place em in the pots & place those pots in the bathtub. Run luke warm tap through a pot until it starts running off heavily... then move on to the next pot & so on... then repeat the cycle 3-4 more times... it doesn't really hurt to over flush here, and we're talkin tap water, so it's pretty cheap & easy in the tub.

This is where it gets kinda pricey... I like mixing the DL, as you do, but will mix a veg strength solution at 3/4 strength & then pH it back up the DL until it is around 6.0~6.3... and I'll run this mix through the pots until the run-off matches my mix in both ppm's & pH. At that point, it's there bro... run's w/o issues, no matter the brand or how you cut it... easy take off. If I didn't have a meter to check the ppm's... I'd just go with enough to match the pH, maybe an extra 500ml~1L after that, jic.

Every other week, pH adjust your mix with the DL again & that will always keep addt'l Ca & Mg available... but I would only use finely pulverized DL in this fashion, not the chunky stuff.

BTW... a ppm meter is pretty darn cheap + vermiculite is a soggy cutting agent for the coir... wouldn't recommend it, just stick with all perlite if you choose to cut. Peace
 
Incognegro

Incognegro

Member
pinecone said:
Try using gypsum instead of DM. The advantage of gypsum is that it won't raise the pH as it breaks down. The other thing you might try is top-dressing with some earthworm castings. Earthworm castings are rich in Ca.

Pine
Click to expand...

Agreed, DM will raise ph (which is a losing battle with DM) and will destroy plants of any kind if given too much of...
 
Incognegro

Incognegro

Member
But looking at the first post... In MY Opinion...the first mistake is using RO water..

In my place of residence, my tap is a GREAT source of Ca, Mg, Mn, and many of the micronutes... no need to change ANYTHING! Haven't used GN brand for anything, so I can't say anything about that... BUT I do know that Canna's line is some of the cheapest shit on the shelf and THE BEST IMO for Coco. I've been growing in coco for about 5-6years now.... and haven't went back yet..
Even when I do drips, RWDC, DWC, whatever, there's coco involved in there somewhere! lol

BIGGEST thing you gotta remember with Coco is this... it's a HYDRO medium, not soil.. all my strains I've grown in coco (probably around 30 now) prefer ph to swing between 5.6-6... fuck to be honest, I don't even own a ph pen anymore... it's that simple with coco... BUT I will be getting one for my new aero-system I plan to make shortly...

Sorry for the ramble....

But all bullshit aside... if ya can afford it...($$wise and with plants) switch to using tap water on some...see what happens :tiphat:
 
C

Coco_nuts

Active member
I dont use RO water, thats just what is used to make that buffer solution concentrate.

My tap water is around 100ppm.

Your methods sound good its just that its going to be a hell of an effort to do that with 30+ 1.5 gallon pots. I would love to just hydrate the coco bricks with tap water (with calcium nitrate and magnesium nitrate added) and be done with it.

Thanks for the advice.
 
Incognegro

Incognegro

Member
Wow, your tap is low... mine is around 250ppm...

If you're really up for the gusto, get your tap water tested... see just how much of what is in there.... like i said I use straight Coco, Canna, and tap :tiphat:...no additives, whatsoever...
 
M

MuricanWeedwolf

Member
pinecone said:
Try using gypsum instead of DM. The advantage of gypsum is that it won't raise the pH as it breaks down. The other thing you might try is top-dressing with some earthworm castings. Earthworm castings are rich in Ca.

Pine
Click to expand...

QFT

Forget the lime, Hydrated Gypsum (HG) and, to a lesser extent, Epsom Salts (ES) are where it's at. While HG is about 5 times less soluble than ES, you shouldn't need more than 1-2 g/L, the higher amount for the initial treatment and the lower amount for general fertigation.

They use it on greens, man :canabis:
Literally, salt buildup is a pretty significant issue on putting greens
 
G

Granger2

Active member
Veteran
First, forget the vermiculite. I wouldn't go higher than 25% perlite. Gypsum [1Tbl/gal of medium], and 2 tsp/gal Earth Juice Microblast. After this 1st app, use 1 tsp of Microblast at least every other watering. You shouldn't need to reapply the Gypsum for approx 6 weeks. Mileage may vary. I reapply with 4 weeks to go before harvest at 1 Tbl per 3 gal pot.

This is after flushing thoroughly with tap. BTW, go to your water company's website. They are required by law to test and post results like every 6 months. Good luck. -granger
 
Weeded1s

Weeded1s

Member
I use ro with 6/9 and never see ca deff.
The nutrients have plenty of ca in them.
Ditch all that other funny stuff like lime etc etc which is making your ph drift up...and just make sure your ph going in is @ 5.8 ph.
I also recommend staying with straight coco ...i no longer like adding other stuff to it these days. :)
Just my 2cenz.
Cheers
 
The.Cook

The.Cook

Member
it depends on the type of coir ur using man

I mean, in the end it's the same, run exactly the same nutrient solution you're gonna use from a few days BEFORE you seed and it will be fine.

if it's a 0 cec coir it will need that time, if it's a prefertilized one could be even enaugh to feed normaly from seed to germ...

I highly suggest an ec meter anyway. I barely check pH but ec is mandatory if you want to know what's goin on
 
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