zeke99
Active member
That's a lot of flushing! It's difficult for me to answer those questions. When I ran drain to waste coco, I never measured runoff, only the inputs. Are your environmentals (temp. humidity) in line?
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Recurring problem with low ph in coco
- Thread starter spaceboy
- Start date
That's a lot of flushing! It's difficult for me to answer those questions. When I ran drain to waste coco, I never measured runoff, only the inputs. Are your environmentals (temp. humidity) in line?
Seems you have 50% Nitrogen as Ammonium.
I suggest using one with high Nitrate Nitrogen ratio; if your pH always goes down in run off.
I was focusing on only measuring inputs but when I started to see issues that progressivley get worse I began measuring everything.
Environmentals are good
I think you may have misread the values
ammoniacal Nitrogen 0.5% - Nitrate nitrogen 4.5%
Ok that makes more sense. So maybe its a result of overfeeding.
And not being able to flush properly.
I would have thought that if the ppms were building up in the medium but it has been going the other way. If ppms are going down i thought ph should go up but i was getting ppms going down and ph going down. seems like one of these values is incorrect and should be ignored id be inclined to ignore the ph at this point. Ill start treating this as an experiment and start giving one more feed consistently and watch the ppms.
Appreciate the responses
OK looks like we need to check roots.
Decaying organic material lowers pH. I doubt it's the coco unless it is very old.
More likely root rot of some kind.
That would explain the deficiency and the pH Drop.
Is your meter calibrated? How often? How's the batteries? These can affect readings.
Decaying organic material lowers pH. I doubt it's the coco unless it is very old.
More likely root rot of some kind.
That would explain the deficiency and the pH Drop.
Is your meter calibrated? How often? How's the batteries? These can affect readings.
Roots look fantastic. Meter was calibrated as soon as I saw issues and again this week.
Might be time for some new batteries but it reads consistently on my water source so I don't think that's the problem but will change them anyway.
I have been focusing on correcting ph to resolve this issue and I can't seem to fix the ph in the runoff. I wonder if this is what some people mean by not trusting the runoff in coco?
I tested the coco in pots with soil ph probe and it came in around 6.5 - 7 which would make more sense since I just flushed and fed at 6.5 for last few days
I'm leaning towards it being a straight deficiency from underfeeding as the ppms were dropping in runoff and hopefully the yellow tips I started getting was from the deficiency progression and not nute burn.
One pot is solidly root bound if that makes any difference. I have seen really big plants root bound in coco pots that look great as long as you keep them from drying out
Feeding at 500ppm ph 6.0 atm and will watch and see what happens
Might be time for some new batteries but it reads consistently on my water source so I don't think that's the problem but will change them anyway.
I have been focusing on correcting ph to resolve this issue and I can't seem to fix the ph in the runoff. I wonder if this is what some people mean by not trusting the runoff in coco?
I tested the coco in pots with soil ph probe and it came in around 6.5 - 7 which would make more sense since I just flushed and fed at 6.5 for last few days
I'm leaning towards it being a straight deficiency from underfeeding as the ppms were dropping in runoff and hopefully the yellow tips I started getting was from the deficiency progression and not nute burn.
One pot is solidly root bound if that makes any difference. I have seen really big plants root bound in coco pots that look great as long as you keep them from drying out
Feeding at 500ppm ph 6.0 atm and will watch and see what happens
Rare Pheno
Member
I would look into diff nutes as well, I won't name drop unless asked but the nutes I use in coco the PH gradually rises, so even if you used ph 5.5 the runoff would be up near ph6 by the next watering. This could also be caused by the brand of coco you are using as well I would assume. My nutes and coco come from the same company and never have any issues with ph ;]
I don't think there is much else to do except change nutes manufacturers. At least test a new line with one pot and see if there is a difference.
If you feed at 6 and it immediately runs out way lower, always, something may be off in the nutrient.
It is certainly odd that you cant get pH up at all
If you feed at 6 and it immediately runs out way lower, always, something may be off in the nutrient.
It is certainly odd that you cant get pH up at all
It's possible through battling the ph issue with all the changing/swinging factors, ph adjustments, flushes, drop in feed.... That at this point their deficient. You did see some better results after the initial fix then they started to deteriorate again. If it were me at this point I would be foliar feeding until they snap back and you get things under control, adding a little Epsom with it.
On another note... Are there any other possible variables...
How do you transition your feed from veg to flower?
Since you have an ro system, are you cleaning your storage res out regularly?
Are these the same genetics as the last run that went successful?
Sometimes simple things change and slip by you. It's worth going over one more time.
Tippy jackson
New member
Wow never seen that with coco.
from the bottom in flower sure,
but from the top, sorry to see that.
I add nitrogen longer into flowering and run
closer to 6.2 to 6.5 plants seem happy.
Been using coco for a long time.
love the stuff, clean easy to mix in your house in the winter.
alot of good answers here, so I will just say so long.
from the bottom in flower sure,
but from the top, sorry to see that.
I add nitrogen longer into flowering and run
closer to 6.2 to 6.5 plants seem happy.
Been using coco for a long time.
love the stuff, clean easy to mix in your house in the winter.
alot of good answers here, so I will just say so long.
One of the big drivers in alkalinity is calcium. Much of coco's buffering is calcium, which sticks well. If we don't give enough in the feed, the plants start to strip this buffering. When we feed again, a lot of our calcium won't run-off as it's stuck to the coco. The feed in suspension then has a lower pH. It's calcium re-appropriated. With RO this might be about the only thing that kept the pH up, so huge drops are likely. One user spoke of the toxicity seen at 5.3 from manganese and boron. At the same time a whole raft of things become unavailable. Many of which can reduce green production.
It's important in coco to keep up the calcium levels, and use some buffering from the tap. We should use some tap in any circumstance but that hard to access calcium carbonate is especially useful for buffing the pH in coco or hydro. Also, we don't see problems from people using too high a pH in coco. More commonly, RO users have a pH that looks high so they add acid, which wasn't needed. Tanks made up with low buffering will be at substrate pH almost on contact. Any acid added, it's useful. With nothing in your tank by RO and feed, what does the acid find to work upon? It's not going to play well.
Personally, I might use RO and feed, then not even look at the pH as it has no staying power once it hits the coco. To this volume of RO I might add 15% more from the tap. I'm looking for a bit of hardness to prop up the pH in the substrate. There are figures to target here, it's not bro science. 30-75ppm of hardness covers most situations. My tap is about 300, so if 15% of my tank comes from the tap, that's about 45ppm. I wouldn't care if it was anywhere between 30 and 100 while trying to figure it out.
Never wash your coco with just water. It removes the buffering. The next feeds will be robbed, putting it back. Washing coco is a setback. You just aim for more run-off. Never less than half feed, with just calmag being an option. There must always be something for the coco, or the coco's own K and Na will make good use of the cec sites. Then when you do add some Ca+Mg this K and Na will be displaced as they have a weaker bond. The result for your feed isn't good, having it's Ca+Mg taken and replaced with K and sodium. It's another setback.
Acidification from excess feed build up.
Acidification from excess acid
Loss of Alkalinity from not adding any
Bacterial action.
Loss of what did raise the pH, as it was eaten
Lowering of the pH through the consumption of some feed elements.
Lowering of the pH because your test equipment sucks...
I feed in the mid 6s, fwiw
It's important in coco to keep up the calcium levels, and use some buffering from the tap. We should use some tap in any circumstance but that hard to access calcium carbonate is especially useful for buffing the pH in coco or hydro. Also, we don't see problems from people using too high a pH in coco. More commonly, RO users have a pH that looks high so they add acid, which wasn't needed. Tanks made up with low buffering will be at substrate pH almost on contact. Any acid added, it's useful. With nothing in your tank by RO and feed, what does the acid find to work upon? It's not going to play well.
Personally, I might use RO and feed, then not even look at the pH as it has no staying power once it hits the coco. To this volume of RO I might add 15% more from the tap. I'm looking for a bit of hardness to prop up the pH in the substrate. There are figures to target here, it's not bro science. 30-75ppm of hardness covers most situations. My tap is about 300, so if 15% of my tank comes from the tap, that's about 45ppm. I wouldn't care if it was anywhere between 30 and 100 while trying to figure it out.
Never wash your coco with just water. It removes the buffering. The next feeds will be robbed, putting it back. Washing coco is a setback. You just aim for more run-off. Never less than half feed, with just calmag being an option. There must always be something for the coco, or the coco's own K and Na will make good use of the cec sites. Then when you do add some Ca+Mg this K and Na will be displaced as they have a weaker bond. The result for your feed isn't good, having it's Ca+Mg taken and replaced with K and sodium. It's another setback.
Acidification from excess feed build up.
Acidification from excess acid
Loss of Alkalinity from not adding any
Bacterial action.
Loss of what did raise the pH, as it was eaten
Lowering of the pH through the consumption of some feed elements.
Lowering of the pH because your test equipment sucks...
I feed in the mid 6s, fwiw
Cactus Wes
Active member
Depending on your grow media, you can amend with diatomaceous earth. It can be watered in. Cheers
Interesting post F-E!
I am testing some coco again with the canna line. I have a few OG leaning hybrids that are still light green. I started out with RO then read a bit about some people mixing with tap. Then read the canna cal mag directions. Last water I didnt have time to let tap sit for a day so I decided to try RO with extra cal mag up to .5ec like I did last water w tap and a bit of calmag. The RO/calmag only mix came out to 6.5 but when I ph'd down it dropped way quicker than w the tap so I totally agree with the idea that tap is good and needed. I had to add alot more down to the tap feeds to get it down to 5.8. I over shot the RO down into the 4's so had to bring it back up. Guess I ought to stick with tap or mix the two.
Any recomendations for slightly light green og's? feeding 1.2-1.5ec ph 5.8. I havent checked runoff since I reset 2 weeks ago (4-5 waterings since, solos up potted to 1gal).
Cheers!
LT
Canna like to use Nitric acid in veg, to make calcium nitrate from the taps calcium carbonate. Giving us both N and Ca. Most people probably don't use it, but it's a part of the feeding program that would address lighter green growth. pH5.8 is also on the low side and doesn't favour N uptake. Light plants and pH below 6 are not an uncommon pairing in coco. It's what keeps me around 6.3
I think the other guy that went off in my Nute thread may have realized what I am starting to feel. Its like this is a line only a fool would run similar to Advance which I would never consider too much bottled water. Some old PBP seemed like it went bad so I decided to try. Then Realized I had to add the zyme because 0-2-1 also added rhizo and boost. Glad I only bought the small additives and if I can get a good coco run I may try MB or Jacks. I will check runoff and raise the ph a bit.
I see the shills at canna are marketing ph up grow and bloom as well as ph down grow and bloom. Not impressed as I continue to find out more is needed for this mix to run smoothly.
Most plants I was having issues with are doing great now though without the ph addition. RH is still low but they look healthy now. It isn't a very cost efficient line coming from calmag and PBP with silica. Less is more.
The more additives a feeding chart is required. I hadn't used one for 15 years! Forgot to even look for one.
Most plants I was having issues with are doing great now though without the ph addition. RH is still low but they look healthy now. It isn't a very cost efficient line coming from calmag and PBP with silica. Less is more.
The more additives a feeding chart is required. I hadn't used one for 15 years! Forgot to even look for one.
