Canna Coir problems - newbie

[JeremyP99]

Hi,

I'm a relative newbie for growing, with a couple of successful plants and a couple of failures. I've just moved to an LED light, and to using Coir rather than compost.

I planted a germinated seed 2 weeks back. I've been following the feeding guide that comes with Canna Coir, using the appropriate nutrients. I'm watering every three days, and not letting the pot sit in the drained water. The mix is circa 2 parts coir to 1 part Perlite.

1. The plant is growing very slowly; only the second set of leaves have appeared. It is no more than an inch tall.

2. The first set of leaves are brown at the tips - very slightly, but clearly so.

3. PH is around 7. I have tried reducing the pH of the feed water with a small amount of lemon juice; the PH reading for the water dropped to just under 6, but the soil remains resolutely at 7+.

4. I had the light quite low over the plant, as LEDs are not hot, but given the brown at the tips of the first leaves, have raised it to c18" above.

What am I doing wrong? I would have expected more healthy growth by now.

I have added an attachment - I hope it shows, it is not recognised by "My Photos" for whatever reason.

 

[drueed]

Hi !
I'll say it's the combination of bad ph .. ( i would say dont mind the soil ph only the water .. get some real ph down ) and the fact you maybe run to high levels of nutes.
I think that the feeding chart is for "grown ups"

 

[wtf]

lemon juice or citric acid is fine for correcting ph

ph - is a ripoff

 

[JeremyP99]

Cheers guys. Will dropping the PH level of the water I use (rainwater run off, left to settle for 24 hours, clocks in at 7 every time) do the same to the coir? It doesn't seem to - the meter I have reads over 7 after every time I have watered the coir. If not, how to I drop the PH of the coir?

And as for feeding, drueed, are you suggesting just watering? No nutes at all?

Thanks for your help. The last watering round, 3 days ago, rather than watering with c1.5 litres, which runs straight through pretty much (though the water meter says the coir is still wet after a couple of day), I "drowned" it with 4 litres for half an hour, and then poured off the excess (pot sits in a waching up bowl in our grow room).

Any further help much appreciated. We have a third set of leaves, but the coir PH is just under 8 today, and the second set of leaves has a yellow tinge at the end.

So - main question is, how do I reduce the PH of the Coir on a permanent basis?

 

[Paul_Revere]

What are you using to check your ph with? If its a meter of some sorts than is it calabriated correctly? I too just made the switch from grow rocks to coco and it's a whole different ball game. 7 ph seems a little high 5.8 to 6 seem to be the sweet spot for me. Also what is the ec or ppm of your feed? If your following cannas feeding chart then I would cut what it says in half, get your ph in check and go from there.

 

[JeremyP99]

Am using a meter with prongs to test. Also tests moisture and light (lumens?). Also litmus paper to test the water. See here - it's cheap and cheerful.

http://compare.ebay.co.uk/like/130586254578?ltyp=AllFixedPriceItemTypes&clk_rvr_id=316087060794&crlp=1_262531_281231&UA=%3F*S%3F&GUID=706285871340a0aa16f79ff7ffb2ee8e&mt_id=635&query=%7Bquery%7D&fitem=130586254578&linkin_id=8070675&kw=%7Bquery%7D&sortbid=11&ff4=262531_281231

 

[dansbuds]

you need a decent PH tester . that one will NOT do . you can get a GH PH test kit just about any hydroshop or pool place . feed at PH of 5.8 & don't worry about the cocos PH .

 

[Paul_Revere]

What dansbuds said is spot on. I wouldn't event attempt coco without a decent ph/ec pen. Look into the Hanna combo meter it's a decent little meter.

 

[Raedwulf]

Hi JeremyP99

I use a hydroponics liquid pH-test kit (and hydro pH-down), it's economical and accurate enough for me - the last grow I had, I got zero nutrient lock-out problems.
I've used alternatives to pH-down (from a tap pH of 8 to 8.5) but found that none of them were as effective - or economical - as the hydro specific stuff.

Apart from the pH, the other thing to watch for is that you don't end-up expelling the air from the coco by 'gurgling' it.
I feed with a watering can and allow the water to soak through gradually - if I see air bubbling to the surface, then I slow down.
I water until I get a run-off then stop, and allow the medium to drain.

Anyway, good luck with your growing.

By the way, There is a coco specific forum you might like to check out, if you haven't already "Growing in Coco Coir" https://www.icmag.com/ic/forumdisplay.php?f=65577

And this thread by bonecarver_OG has helpful tips / discussions etc (but, be warned, it's 90-odd pages long) "The Hand Watering coco thread" https://www.icmag.com/ic/showthread.php?t=46490

 

[Guest 263194]

Accurate PH is the key point growing in coco coir. you CAN'T do that with lemon juice, not enough buffer solution. As soon as you water ph will swing inside. Also, what water are you using?.

 

[rasputin]

What kind of nutes are ya using, JeremyP? I'm growing in coco and haven't pH'd a thing. No issues. Just saying, it can be done without meters and the like.

 

[drueed]

As most peoples said .. cut the nutes by half and get a precise PH meter and Real Ph down .

Cheers

 

[JeremyP99]

Accurate PH is the key point growing in coco coir. you CAN'T do that with lemon juice, not enough buffer solution. As soon as you water ph will swing inside. Also, what water are you using?.

Water is rainwater, left to sit for 24 hours from the tank (to warm up - cold here at the moment). PH acc to the meter & Litmus paper is bang on 7.

I have a bottle of PH Down.

Lots of good advice thanks - who can distil it into a few steps?!

FYI - One plant in a well-sized plastic pot, 2:1 Coirerlite. Pot standing in a washing up bowl to catch run off.

1. Get a decent PH meter
2. What nutrient program to follow
3. How often to water and how much
4. How much PH down for however much water I am using

Many thanks to all who have posted here - I am sure I will have more questions

 

[JeremyP99]

What kind of nutes are ya using, JeremyP? I'm growing in coco and haven't pH'd a thing. No issues. Just saying, it can be done without meters and the like.

Am using the Canna Coir nutrient range, and sticking to the feeding timetable they provide.

BTW, what is "EC"?

 

[JeremyP99]

Hi JeremyP99

I use a hydroponics liquid pH-test kit (and hydro pH-down), it's economical and accurate enough for me - the last grow I had, I got zero nutrient lock-out problems.
I've used alternatives to pH-down (from a tap pH of 8 to 8.5) but found that none of them were as effective - or economical - as the hydro specific stuff.

Apart from the pH, the other thing to watch for is that you don't end-up expelling the air from the coco by 'gurgling' it.
I feed with a watering can and allow the water to soak through gradually - if I see air bubbling to the surface, then I slow down.
I water until I get a run-off then stop, and allow the medium to drain.

Anyway, good luck with your growing.

By the way, There is a coco specific forum you might like to check out, if you haven't already "Growing in Coco Coir" https://www.icmag.com/ic/forumdisplay.php?f=65577

And this thread by bonecarver_OG has helpful tips / discussions etc (but, be warned, it's 90-odd pages long) "The Hand Watering coco thread" https://www.icmag.com/ic/showthread.php?t=46490

Cheers - will check the guides when I have walked the dogs!

 

[JeremyP99]

What dansbuds said is spot on. I wouldn't event attempt coco without a decent ph/ec pen. Look into the Hanna combo meter it's a decent little meter.

How does this look? There are other models available, it seems, but all over £100.

http://www.ecrater.co.uk/p/6725177/hanna-hi-98129-grochek-ph-ec

 

[drueed]

You can go with the PH and EC as separate meters .. way cheaper !

Like this one !

 

[JeremyP99]

Canna feeding guide

Canna feeding guide

And here is the feeding guide that comes with the various Canna nutrients - and which I was adhering too. Last two feeds, after advice here, have been plain water. Flooded the pot, left it half an hour, then drained it.

https://www.icmag.com/ic/attachment.php?attachmentid=153697&stc=1&d=1329404850

Sorry - don't seem to be able to load an image inline. Have uploaded two pictures, but when I click on "insert" (my photos) it says I have no pictures uploaded. Confused...

 

[JeremyP99]

Cheers - that's more like it! Do you have a link for a cheaper EC meter? And is that as necessary as the PH? Not used these, as I did a pretty hit and miss set of grows with compost; got a couple of good low yield plants, and a couple that were no good - had Metal Halide lamps, and the grow room was too hot, and I am not in a position to put in an extractor fan, hence changed to LED.

Boo! Shipping for the link you sent me is as much as the meter, doubling the price to £48. Will look elsewhere - that is a total rip off for internal mail

 

[dansbuds]

One more thing i noticed is don't let your buckets sit in the runoff water . it will cause a salts build up in the coco & really mess up the plants . when feeding to run off DO NOT LET THE PLANTS SIT IN THE RUN OFF WATER !!! drain it out ASAP .