The problem with maintaining PH in coconut

[Bobcat.Branch]

I thought, because it says everywhere, that you are supposed to check the PH at the drain every time you water, and if it's outside the recommended range, then you are supposed to top up the water until the correct PH comes out of the bottom. As you wrote to water when 20% comes out, 20% of what? Of the volume of the pot or the volume of the watering can? If I pour four litres into a pot, about one litre will come out.

Yes, 20% of the volume you put in. So, 4l in and 1l out is 25%, close enough. I would wait until time to water again, mix everything in the correct order, pH the mix to your specification, then water to 20% runoff. Once consistent with this method, you should see better runoff results.

I've always grown in Coco/perlite with an ebb & flow system, so my pots would get soaked then drained back to the reservoir. I would test the reservoir daily for EC changes (indicating that plants were feeding or not and for nutrient/salts buildup). ph would drift in the reservoir over a few days to a week and I always aimed to start at the bottom of my pH target and let it drift up to the higher end. By the time that happened, EC was down (plants were feeding), and it would be time to change out the reservoir contents for another 5 to 7 days.

I realize this isn't your method of growing, but hopefully it gives you some insight into what's happening in your pots.

You're giving fresh food and carefully pH'd water every time, so you actually have better control. I think proper methods, good pH and EC targets (for each phase of growth), and being consistent are all keys to success with coco. Coco isn't hydro, it isn't soil. It's somewhere in between. That means pH targets are somewhere in between, as well. pH is all about nutrient take up and availability. Congrats to people like us! We've chosen a Frankenstein medium and have to hoe our own road.

Well maybe not anymore for me... I've gone back to soil as of a few days ago.

 

[OldOneEye]

I thought, because it says everywhere, that you are supposed to check the PH at the drain every time you water, and if it's outside the recommended range, then you are supposed to top up the water until the correct PH comes out of the bottom. As you wrote to water when 20% comes out, 20% of what? Of the volume of the pot or the volume of the watering can? If I pour four litres into a pot, about one litre will come out.

You are running in circles.
Ph your water/feed to proper range for the feed being used.
Veg nutrients: ph to 5.8 to 5.9
Early flower nutrients: ph yo5.9 to 6.0
Late flowering nutrients: ph to 6.1 to 6.2
After flushing use those numbers, you will be golden

 

[hoo]

OKAY. I'll stick with it. Thank you.

 

[Choppr]

I thought, because it says everywhere, that you are supposed to check the PH at the drain every time you water, and if it's outside the recommended range, then you are supposed to top up the water until the correct PH comes out of the bottom. As you wrote to water when 20% comes out, 20% of what? Of the volume of the pot or the volume of the watering can? If I pour four litres into a pot, about one litre will come out.

Ive been in Coco for over 10 years - "I have never checked run-off pH" - I dont know where your read this but its bad Info! "The pH of your mix solution is what is in the media" till the next watering!- Your mixing is off too, you pH after all the nutrients are mixed into the Solution, pH to 5.6-5.7 pour in enough solution to get 20% run-off every time, and check ppm/ec of run-off only!, your run-off will always be higher than what your pouring into the pot. If your running 5 gal pots, it takes about 1.5-1.75 gal to have about 1liter or more of run-off.

*I water 1.75gal to run-off every other day in 5 gal pots - right now in flower my mix solutions are around 800ppm - my run-off is about 1000ppm - Im fine with that. If your plants look healthy your good to go!

 

[Choppr]

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[hoo]

After flushing use those numbers, you will be golden

Just to be clear: If I understand correctly. Should I water it today with 20 litres of stagnant water (20l pot) with water without fertilizer with the correct Ph, leave it for 24 hours and then water with fertilizer?

 

[OldOneEye]

Just to be clear: If I understand correctly. Should I water it today with 20 litres of stagnant water (20l pot) with water without fertilizer with the correct Ph, leave it for 24 hours and then water with fertilizer?

I wouldn't really worry about ph of flushing water. Coco doesn't absorb water, so it will clean the coco of any toxicity especially, let it drain well. Your plant won't take in any nutrients, and you don't want it to yet.
Then feed with appropriate ph level for nutrients. Know your plant will take what it needs from the water and leave the rest.....why you must water to about 20% runoff off.

 

[Grownsince95]

So many more plants get killed by love than by neglect!!! The pics I saw on this thread are of beautiful healthy plants! I've been growing in coco for a long time and I never check runoff ph. Plant roots change the ph by doing their thing anyway. Thats why we always water until runoff with coco, no exceptions. This ensures the root zone is at least at the proper starting point every watering.

You want to check the EC of the runoff water, not the ph. This will let you know if you're feeding them too much

Less is more

Don't over think it and fuss with the ladies too much, they like shit steady and consistent.

 

[hoo]

I'm taking your advice. I'll water with Ph 5.9 up to 20% runoff. I'll pour in 6 litres of water and drain about 1.5 litres. I haven't given up yet, and just for fun I'm still measuring the Ph on the drain :-). I know it's fine. It's still Ph 5.5.
The plant looks good, except that three leaves have brown/rust spots on the edges of the upper leaves between the veins. The leaves were dryer to crisp.

This also happened to me at the beginning of my problems. These spots plus the yellowing between the veins were appearing and based on reading on the interwebs, I read to check the Ph on the drain as it is a calcium deficiency and may be caused by poor Ph. Well, I started to measure the drain and found that it was leaking a different Ph and I started to address it because I thought it was causing the deficiency.

I have one more question. When I water with 1.8 EC water, after two days, 2.4 EC comes out of the pot and I have to cut back to 1.8. I always get 2.4 EC coming out of the pot. That always happens to me. If I water with regular water, after two days I get 1.2 EC. How do you recommend fertilizing. Should I always top up when I water to 1.8, or just fertilise every 4 days so that the EC comes out to about 1.8 after watering?

One more thing that was mentioned. If I have a grow room temperature of 27C, does that mean the leaf temperature is 23C, so at flowering time I can easily have 30C in the grow room because the nal istech will be 26C? Someone here wrote that the leaf temperature is 4C lower than the ambient temperature.