Brown spots and curling upwards...

raCURE · Feb 17, 2021

Hello,

Any idea what the problem may be?

HPS set at 400w
Coco
Feeding maxibloom at 7g per 4 litre PH 5.8-6.1
Temp 26~
Humidity 65~
Feeding 1 litre every two days, reduced this to 600-700 last couple feeds.

Over feeding? Deficiency?

Pictures to follow, any help will be greatly appreciated.

PS no sign of any pests under leaves or on the soil.

raCURE · Feb 17, 2021

Was happening to one plant to start but 3-4 showing same or similar problems.

raCURE · Feb 17, 2021

So far I’m putting this down to over feeding and plan on flushing 700-1 litre a day for a few days but will hold off for you experts

bigpeter · Feb 17, 2021

run off ppm?

FletchF.Fletch · Feb 17, 2021

Looks like too much fertilizer. As the area around the roots dries after being fed, it can create a concentrated spike in ec right around the base of the plant. Flush with ph adjusted water and measure your runoff (the water that drains out) ph and ec/ppm to be certain.

GoatCheese · Feb 17, 2021

I’d say that’s from the coco drying out too much. The coco in your photos looks quite dry (light brown color) to me. Coco is a hydro medium, it should not be treated like soil. Coco is supposed to be at least a bit moist all the time.

Check out the “hand watering coco”-thread at coco-sub forum for more info

raCURE · Feb 17, 2021

Will check the run off PH and ppm tomorrow and report back.

Do you think it would be better to water/feed coco DAILY but less rather than more and every two days?

Will also read that thread.

Thanks guys!

GoatCheese · Feb 18, 2021

raCURE said:
Will check the run off PH and ppm tomorrow and report back.

Do you think it would be better to water/feed coco DAILY but less rather than more and every two days?

Will also read that thread.

Thanks guys!

Yes, daily. Water little at a time - slowly, so that the coco has some time to suck the moisture in, till you see little coming out the bottom.

..people who use drippers many times have them on three times a day

bigpeter · Feb 18, 2021

raCURE said:
Will check the run off PH and ppm tomorrow and report back.

Do you think it would be better to water/feed coco DAILY but less rather than more and every two days?

Once a plant growing in coco is established with a decent root system it can take multiple fert/waterings daily. The runoff shouldn't get to be 200ppm above what goes in, if it does flush untill it is within range.

50shadesofgreen · Feb 18, 2021

I do agree with folks about watering in coco - you should not let it dry ever. It is basicaly hadroponic medium...coco itself has zero fertilisers in it. It has only what you feed it with. And you should not let it dry otherwise you can burn your plant with spike of nutes.

This never happened to me in coco because I know I should not let it dry, but but what I was going to say is I had few years ago exactly same looking plants as you in organic soil fed with organic nutes. And I did fixed it by adding more nutes and calcium. I think problem was celcium deficiency, because I did managed to fix plants when I added more nutes (organic Biobizz or Plagron...not sure which bottle I had at that time, but they are prrety much the same) and also I added calcium - 2ml per 1 l of water. After week plants were more green and stopped creating more of these brown spots. HOwever those sick leaves affected by these brown dots died and dried off, so plants definitely suffered a lot.

I am not sure what fertilisers are you using but those designed for coco have usually higher amount of calcium in them already, because coco has 0 calcium itself. Not like soil.... So if you are using correct nutes calcium should not be cause of your problem....

Check PH runoff and keep your coco wet all the time.

raCURE · Feb 18, 2021

Update:

I was advised to flush for several days so I basically fed PH’d tap water.

Before //
PH: 6.1
EC: 1104
PPM: 0552

Runoff //
PH: 5.7
EC: 1618
PPM: 0798

I don’t actually truly understand the EC & PPM numbers so will need to do some reading.

A couple of the browned leaves today have turned a light shade of green.

raCURE · Feb 18, 2021

Just a read up on PPM and EC over at RWS, interesting ! :canabis:

GoatCheese · Feb 18, 2021

raCURE said:
Update:

I was advised to flush for several days so I basically fed PH’d tap water.

Before //
PH: 6.1
EC: 1104
PPM: 0552

Runoff //
PH: 5.7
EC: 1618
PPM: 0798

I don’t actually truly understand the EC & PPM numbers so will need to do some reading.

A couple of the browned leaves today have turned a light shade of green.

The higher EC on the run off is because you have watered the coco too little and it’s a mineral based nutrient so there’s some salt build up
..so you should flush the coco/pots with mild pH adjusted nute solution, a proper flush to rinse off the build up off the coco, and then give them some normal strength nutes.

In general when you’re using mineral based nutes you should flush the medium once a week with mild pH adjusted nute solution.

raCURE · Feb 18, 2021

GoatCheese said:
The higher EC on the run off is because you have watered the coco too little and it’s a mineral based nutrient so there’s some salt build up
..so you should flush the coco/pots with mild pH adjusted nute solution, a proper flush to rinse off the build up off the coco, and then give them some normal strength nutes.

In general when you’re using mineral based nutes you should flush the medium once a week with mild pH adjusted nute solution.

Thanks GoatCheese.

I plan on switching to Canna Coco line from Friday so that should help the situation?

Appreciate the help!!

GoatCheese · Feb 18, 2021

raCURE said:
Thanks GoatCheese.

I plan on switching to Canna Coco line from Friday so that should help the situation?

Appreciate the help!!

I have never used Canna nutrients of any kind and it’s also mineral based so you should do the flush once a week, but i’m sure it’s a good line once you get to know it. Read/ask about it at the Nutrients and Fertilizers sub-forum or the coco sub-forum.

I’m not much of a coco grower,I grow mainly in soil, thou I’m doing few little hand watering coco plants atm using BioBizz nutes, so I’m not to best person to give too much advice on coco growing.

I think your main problem was/is related to watering, as already mentioned, but other than that the leaves on your plants looked ok regarding the nutrient strength, not under fed or badly over fed, so I’m sure you’ll be fine when you get your coco watering in check = coco needs to be fairly moist all the time unlike soil.

TanzanianMagic · Feb 18, 2021

raCURE said:
View Image

View Image

Was happening to one plant to start but 3-4 showing same or similar problems.

How about showing all of the plant?

Before //
PH: 6.1
EC: 1104
PPM: 0552

Runoff //
PH: 5.7
EC: 1618
PPM: 0798

This is pretty clear.

The EC meter is of the EC:uS/CM² variety. There is a good conversion table here, although it basically is EC x 1000.

https://dutchmasternutrients.com/growers-guide/ppm-vs-ec/

Water going in: 1.1 EC and 6.1 pH. Runoff: 1.6 EC and 5.7 pH.

The medium needs to be flushed again. Sometimes the medium needs to be flushed slowly and several times, because nutrients basically dry into the medium and release slowly.

The runoff is 0.5 EC higher and the pH 0.4 lower, which indicates there are too many nutrients in the medium.

raCURE · Feb 21, 2021

Small update;

Flushed the plants with PH’d water for 3 days, which they seemed to like and bought some canna products (full line basically haha) so today was there first feed and all had a litre each.

Is 1 litre daily too much for the size or...?

GoatCheese · Feb 21, 2021

raCURE said:
Small update;

Flushed the plants with PH’d water for 3 days, which they seemed to like and bought some canna products (full line basically haha) so today was there first feed and all had a litre each.

Is 1 litre daily too much for the size or...?

View Image

You should go by how much moisture the coco still has, which should at all times be moist, not by a fixed amount of nutrient solution. Some plants drink more than others.
Environment plays it’s part; humidity, fans moving air, how hot is it in the grow area and so how much moisture evaporates out of the coco etc. So it’s difficult to say how much they should drink.

Lift the pot when you have watered them and feel the weight in your hands and try learn to estimate the moisture content by how heavy the pot feels in your hands ..you’ll get better at it in awhile, the same trick works for soil grows as well. Keep lifting the pots thru their 12/12 day and try to get a feel how much they’re drinking.

If the plants will get big you may have to start watering them two-three times a day cause the coco will dry out quite quickly but time will tell.

GoatCheese · Feb 28, 2021

How are things going?

Are your plants looking better?

Brown spots and curling upwards...

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