Higher Ec runoff, bottom feed.

D

Daskalot

Member
Hi to everyone,

One question for the more experienced.

We are running a grow of a.haze, in 70-30 coco perlite mix. Canna coco nutrient. The watering has been from the bottom. We pour water in trays, and plants drink the water in about 20-30min. We feed every second day. Today its been 7week of flowering and i decided to test the run off (although there is no run off in bottom feeding) I took water with Ph of 6.0 and EC of 2.2 and poured it on the plant from top until runoff 20%. The runoff EC i got was 3.6.
Can someone share their opinion? Do i need to wash them with plain ph'ed water? Or is it better to give them half strength nutes? Does run off EC matter at all with bottom feeding? I do not get it how roots get nute lockout when water is not poured from top??

I absolutely have no symptoms of nutrient burn, except that leaves might just a little more dark green.

Should i keep going like until now and finish the grow, or should i do something in order to save the plants? Will this hurt their yield?

Thanks
 
rkymtnman

rkymtnman

Well-Known Member
i'm not a coco expert but i would top feed twice a day with nutes somewhere in the 0.8 to 1.0 range until you get runoff that is much less than 3.6. sounds like you just have salt buildup due to lack of daily runoff.
 
xtsho

xtsho

Well-Known Member
First, 2.2 EC is much too high. Lower it.


Second, As you soak up that nutrient solution from the bottom and the moisture evaporates you're left with the salts in the coco. When you flush with a lower EC solution you're also flushing what's already in the coco and that will add to the EC. Which is why testing runoff EC and pH is a poor method of determining what's going on in the growing media at the root zone of the plant.

Third, I would switch to a top fed watering system. Moist people water until slight runoff from the top. I use blumats which are still top feed but there is no runoff.


Good luck
 
D

Daskalot

Member
The grow is very big its impossible to do top feeding. It would take two days just to finish the feeding.
As things are, should i flush with only ph’ed water, rinse with lower nutes or not do anything at all?
 
Renfro

Renfro

Well-Known Member
Daskalot said:
As things are, should i flush with only ph’ed water, rinse with lower nutes or not do anything at all?
Click to expand...
Whatever works best to prevent salt buildups. Perhaps a weekly flush?

Feed as weak as you can without getting any deficiencies, so salts will build up slower. Once you determine how long you can go between flushes without seeing excessive EC on the runoff or any signs of burn or lockout then you know to set the flush interval to something shorter than that.
 
pajautus

pajautus

Well-Known Member
I bottom feed my coco plants, but give them a mini flush weekly from the top, with about 0,5ec worth of nutes + enzymes..
works like a charm.. just my 2cents..
 
xtsho

xtsho

Well-Known Member
Daskalot said:
I follow canna coco table. The EC from the table for this week is 2.2 so i follow that EC.


So dont you have salt buildup also? If u dont have run off its the same situation as mine.
Click to expand...
Not the same situation at all. I run a much lower EC. Like around 1.5. And I only run base nutes. I don't get salt buildup. Healthy plants from start to finish.
 
lee1000

lee1000

Well-Known Member
I'm doing a bottom feed in my grow right now. 12x gallon buckets 70/30 perlite/vermiculite, all hooked together with pipes running from one another and to one empty bucket hooked up to the feeder barrel. It works great and is super easy. I do flush from the top with a very weak feed every 2 weeks though from the top to get rid of a lot of salt build up. I guess they're pretty much closed off hempy style.

I find feeding plants to be a pain in the ass, especially when I have to juggle under all of that growth. It just puts me off a little. The way I do it, feeding is finished within a minute.
 
V

vertnugs

Well-Known Member
With no way of fertigation from the top you shouldn't be using such high feeds with a bottom feed system.

Every other day fertigation is allowing your coco/perlite mix to get too dry.As your water evaporates and plant uptake occurs salts build.This is where lockout can occur,not from top feeding.Top fed allows you to rinse the pot from top out the bottom.

At 7 weeks it may be a lost cause,you're going to notice it in the finished product more than likely.

If it were me i'd drop it down to 1/4 strength nutes and hope for the best.
 
Renfro

Renfro

Well-Known Member
Id really like to see some pictures of these plants and this grow thats so large to water.

Building an auto-watering top feed is going to be the way to go. Consider this before your next round as bottom feed is a poor way to grow. Salt buildups can make for big time yield losses and poor flavor.
 
gr865

gr865

Well-Known Member
I agree bottom feeding coco is not enough and watering every other day is not good either.
As many suggest if you are going to run coco/perlite you need to convert to a top feed auto system.

DIY Auto feed system
20190918_101836 .jpg

Manifold inside of tent, this is an older pic from another grow, I am using all 8 ports at present.
20181005_095126 (2).jpg

These are the emitters I am using, very good distribution of solution.
20181005_095120.jpg You can see the quick disconnects, this is so the plant can be moved from the tent to perform maintenance on them.

This system has served me well.
 
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