Nutrient question for soil

[Mandragoras]

Hi guys! i try to figure out 2 things. In a soil grow using nutrients 18-18-18
a) what would be the frequency of feeding nutes to the plants? one every 3 waterings?
b) what would be the EC of the feeding mix if i use this 18-18-18?



Thanks a lot in advance

 

[az2000]

I feed every watering. I don't understand the rationale for feeding 2-3x more one time, then nothing a time or two. To me it seems like it would be at least the same (if not better) to feed the proper amount every time. But, there are a lot of people who alternate feed/water. Maybe there's a reason to do it. I'd recommend doing a constant feed for an entire grow. After you know the proper amount to feed with every watering try a grow where alternate feeding twice as much followed by feeding nothing (water only). See how it compares. But, I think it would be better to start with constant feeding. Easier to determine what the proper amount is to feed.

I feed 16-16-16 at about 400ppm (0.8 EC) in veg. During aggressive veg I might go to 500ppm (1.0 EC). In flower I mix 16-16-16 with 4-26-26 to increase PK. I feed closer to 500-550ppm (1.1 EC). If I use a bloom booster once or twice I go to 700ppm (1.4 EC).

What does the label on your nutrients say? When you can't find anyone who have actually grown with a nutrient it's customary to use whatever the label says at half strength. You might mix half what the label says and see how that compares to what I described.

It also depends on whether your soil has any nutrients mixed in. It's better if it doesn't (unless you're using organic soil), then you're in complete control. If the soil has nutrients you'll want to reduce what you feed.

When I feed my 16-16-16, 1/2 tsp gives me about 400ppm.

I strongly recommend that you measure your runoff ph and EC. If you feed too much you'll see the ph drop, probably a 2-3 weeks into flower. If you see the runoff ph going lower, you'll be able to take corrective action before it gets below 5.5 and problems begin. EC will also rise, above 2.4 by the time problems begin. If you see ph and EC following a trend in those directions the result will be a lot better than if you didn't measure your runoff, didn't see the trend, and only know there's a problem when the plant starts showing deficiencies due to lockout.

 

[Mandragoras]

I feed every watering. I don't understand the rationale for feeding 2-3x more one time, then nothing a time or two. To me it seems like it would be at least the same (if not better) to feed the proper amount every time. But, there are a lot of people who alternate feed/water. Maybe there's a reason to do it. I'd recommend doing a constant feed for an entire grow. After you know the proper amount to feed with every watering try a grow where alternate feeding twice as much followed by feeding nothing (water only). See how it compares. But, I think it would be better to start with constant feeding. Easier to determine what the proper amount is to feed.

I feed 16-16-16 at about 400ppm (0.8 EC) in veg. During aggressive veg I might go to 500ppm (1.0 EC). In flower I mix 16-16-16 with 4-26-26 to increase PK. I feed closer to 500-550ppm (1.1 EC). If I use a bloom booster once or twice I go to 700ppm (1.4 EC).

What does the label on your nutrients say? When you can't find anyone who have actually grown with a nutrient it's customary to use whatever the label says at half strength. You might mix half what the label says and see how that compares to what I described.

It also depends on whether your soil has any nutrients mixed in. It's better if it doesn't (unless you're using organic soil), then you're in complete control. If the soil has nutrients you'll want to reduce what you feed.

When I feed my 16-16-16, 1/2 tsp gives me about 400ppm.

I strongly recommend that you measure your runoff ph and EC. If you feed too much you'll see the ph drop, probably a 2-3 weeks into flower. If you see the runoff ph going lower, you'll be able to take corrective action before it gets below 5.5 and problems begin. EC will also rise, above 2.4 by the time problems begin. If you see ph and EC following a trend in those directions the result will be a lot better than if you didn't measure your runoff, didn't see the trend, and only know there's a problem when the plant starts showing deficiencies due to lockout.

very nice answer!!! i just want to clarify something. When you say you feed them at 0.8 in veg, do you count your water EC to this? I have a water of 0.4 EC, so that would mean that i up the ec with a 0.4 or 1.1 in my case?

 

[az2000]

very nice answer!!! i just want to clarify something. When you say you feed them at 0.8 in veg, do you count your water EC to this? I have a water of 0.4 EC, so that would mean that i up the ec with a 0.4 or 1.1 in my case?

Yes, I count the final EC. My water is over 1.0 which doesn't leave much room for nutrients. So, I use reverse osmosis water which is about 0.1. I add 2ml calmag (a little more in flower) by default just to bring the water up to what would have been an acceptable EC like yours, replacing the minerals that should have been present in the water. (Some people say I should be able to mix RO water with my tap water. I haven't tried that yet.). Then a ~1/2 tsp of fertilizer which brings it up to about 0.8-1.1.

As long as you're in that range I wouldn't worry much. If you don't get nute burn or deficiency which are both fairly immediate, then you'll want to watch for salt buildup as I described which is a slow process and won't be seen until your plant starts having deficiencies later in the grow. Tracking runoff ec and ph will be invaluable if a problem arises later.

Be sure not to water too frequently. Let the soil dry before watering. The soil's ph rises as it dries, if you keep it too moist you can cause something like salt buildup (nute lockout) because the ph range the plant experiences is held too low.

Because you're growing in soil, I suggest you read "Teaming with Microbes" (http://ge.tt/9LYCbnC/v/1). You don't need to do anything other than feed the plant using the fertilizer you have, but eventually you'll want to feed the soil biology. I add Botanicare Liquid Karma, usually 1/4 tsp molasses, 1/2-1 tsp fish emulsion, rhizo blast in veg. If you read the book you'll be prepared to supplement with organics. But, I'd keep it simple for now.

One thing you probably want to add in veg is a silica product like Botanicare Silica Blast. Silica makes the plants tougher, resistant to heat, cold, drought, pests.

 

[Aeroknow]

Hi guys! i try to figure out 2 things. In a soil grow using nutrients 18-18-18
a) what would be the frequency of feeding nutes to the plants? one every 3 waterings?
b) what would be the EC of the feeding mix if i use this 18-18-18?



Thanks a lot in advance

I'm with az2000 on this, and would rather feed every time also. But I do understand why people do the other.

If you don't/can't water with lots of nutrient solution every time, until plenty of run-off is achieved, you would want to either feed a relatively low EC every time (I would still flush every other week though, as salts will build up).
Or run a bit higher EC than that and alternate feed water feed. Or feed feed water, whatever is clever. Again, this is if you don't water with lots of nutrient solution, achieving lots of run-off.
Now, I am more of a higher EC kind of guy(1.7ish), feed everytime, but water/feed until i get lots of run-off everytime. Sort of a mini-flush every time if you will. Keeping the EC at the roots in check, and rite exactly where I want it to be.
I grow in containers up on trays to be able to direct all of the run-off where I want it go. Which is why I'm able to feed with as much nutrient solution as I want
Hard to do that with pots on the floor. <<<<<<what a mess!
There's no right or wrong way. People would say I waste nutes. I don't give a shit.
Does this make any sense?

 

[az2000]

Now, I am more of a higher EC kind of guy(1.7ish), feed everytime, but water/feed until i get lots of run-off everytime. Sort of a mini-flush every time if you will. Keeping the EC at the roots in check, and rite exactly where I want it to be.

I agree, I've done that. In theory, if we feed exactly what the plant needs there wouldn't be any leftovers in the form of salt buildup. But, I think doing so is like telling a child "nothing more until you finish what's on your plate." By feeding with significant runoff (20% or more) it's like removing the partially eaten plate with a new one. Rebalancing the NPK, trace minerals, etc. I.e., at different stages of activity the plant may need more of some nutrients than others. Displacing what's there resets the nutrients. The more we displace, the less likely it is for salt buildup, and therefore possible to feed stronger.

I suppose that's better for synthetic nutrients than organics. If you feed organic components, that's a little more longer-acting, you're promoting microbes you don't want to wash away the "good stuff" they live on, etc.

I'm feeding Grow More Sea Grow which contains synthetic and organic components. So, I've been doing fewer large-runoff feedings.

 

[Mandragoras]

Yes, I count the final EC. My water is over 1.0 which doesn't leave much room for nutrients. So, I use reverse osmosis water which is about 0.1. I add 2ml calmag (a little more in flower) by default just to bring the water up to what would have been an acceptable EC like yours, replacing the minerals that should have been present in the water. (Some people say I should be able to mix RO water with my tap water. I haven't tried that yet.). Then a ~1/2 tsp of fertilizer which brings it up to about 0.8-1.1.

As long as you're in that range I wouldn't worry much. If you don't get nute burn or deficiency which are both fairly immediate, then you'll want to watch for salt buildup as I described which is a slow process and won't be seen until your plant starts having deficiencies later in the grow. Tracking runoff ec and ph will be invaluable if a problem arises later.

Be sure not to water too frequently. Let the soil dry before watering. The soil's ph rises as it dries, if you keep it too moist you can cause something like salt buildup (nute lockout) because the ph range the plant experiences is held too low.

Because you're growing in soil, I suggest you read "Teaming with Microbes" (http://ge.tt/9LYCbnC/v/1). You don't need to do anything other than feed the plant using the fertilizer you have, but eventually you'll want to feed the soil biology. I add Botanicare Liquid Karma, usually 1/4 tsp molasses, 1/2-1 tsp fish emulsion, rhizo blast in veg. If you read the book you'll be prepared to supplement with organics. But, I'd keep it simple for now.

One thing you probably want to add in veg is a silica product like Botanicare Silica Blast. Silica makes the plants tougher, resistant to heat, cold, drought, pests.

awesome!

 

[Mandragoras]

I'm with az2000 on this, and would rather feed every time also. But I do understand why people do the other.

If you don't/can't water with lots of nutrient solution every time, until plenty of run-off is achieved, you would want to either feed a relatively low EC every time (I would still flush every other week though, as salts will build up).
Or run a bit higher EC than that and alternate feed water feed. Or feed feed water, whatever is clever. Again, this is if you don't water with lots of nutrient solution, achieving lots of run-off.
Now, I am more of a higher EC kind of guy(1.7ish), feed everytime, but water/feed until i get lots of run-off everytime. Sort of a mini-flush every time if you will. Keeping the EC at the roots in check, and rite exactly where I want it to be.
I grow in containers up on trays to be able to direct all of the run-off where I want it go. Which is why I'm able to feed with as much nutrient solution as I want
Hard to do that with pots on the floor. <<<<<<what a mess!
There's no right or wrong way. People would say I waste nutes. I don't give a shit.
Does this make any sense?

definately, very similar to mine... the run off method is what i do too. It must have been the salt build up then than made plantts look bad, then i flushed them twice nad had signs of underfert, mainly Nitrogen, i believe. So i watered them again with solution of 0.7 and now i wait for change... mother plants and clones they are, about 14 inches the bigger one, but with 5-6 shots each.

I ll post again soon to tell you if the issue was fixed.

I possibly overwatered too , i see stunted growth and hanging leaves at the edges of them. I know for sur now that i have to water them lighter. But the problem i think happened from the many flushes they took until now.... If problem does not fix in new shots in a couple of days i ll try and just trasplant them in new organic soil and just pH water them around 6, until they show the first signs of neediing nutes. As the soil has some nutes inside already, i believe this would be better method.