Coco runoff EC very low

I'm growing in 20L (7 gal) airpot and watering once per day. The plant has been vegging for 6 weeks. Lately I've had to water more to produce runoff, 1.8L today produced runoff of 300ml. However, the runoff EC is very low, about 650us/cm with inflow of ~1200us/cm. It's been like that for a week now. Any ideas what's causing this?

I’m having the same issues have you solved this?

I never check the run off for ppm or pH.
As long as what you put in is correct and you have substantial run off......you won't have issues in coco.

It's normal with new coco give it some time your run off ec will go up.
Apparently it's caused by cation exchange robbing the nutrient or whatever nutrients.

Water to runoff twice a day.

I can't check my runoff in coco because I don't have any. And when I did water until runoff I never once even thought to check it. If the plants are healthy what's the point? Too many people go looking for problems and then end up creating them trying to fix a problem that doesn't exist. If the plants are healthy just keep doing what you're doing and use the meters to adjust what you're feeding not to check what runs out the bottom.

You need to be feeding the plants enough water with nutes to have at least 20% runoff, I feed my plants that are in 5 gallon pots 1-2 gallons twice in a 16 hr period, they are vegging.

Piper84 said:

You need to be feeding the plants enough water with nutes to have at least 20% runoff, I feed my plants that are in 5 gallon pots 1-2 gallons twice in a 16 hr period, they are vegging.

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100% coco and blumats. 0% runoff. My plants grow just as good as they did before I started using blumats and was watering until runoff.

I think that if you are doing frequent fertigation in coco you don't really need to worry about watering to and collecting run-off, as xtsho has said. The frequency of fertigations will prevent the buildup of salts that you would otherwise feed to runoff for.

guitarguy10 said:

I think that if you are doing frequent fertigation in coco you don't really need to worry about watering to and collecting run-off, as xtsho has said. The frequency of fertigations will prevent the buildup of salts that you would otherwise feed to runoff for.

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That’s not the case, I feed 3x during the light period every day and the ec has risen.

xtsho said:

I can't check my runoff in coco because I don't have any. And when I did water until runoff I never once even thought to check it. If the plants are healthy what's the point? Too many people go looking for problems and then end up creating them trying to fix a problem that doesn't exist. If the plants are healthy just keep doing what you're doing and use the meters to adjust what you're feeding not to check what runs out the bottom.

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Must be your nutes as i feed low also.Could be the plants drying up a little too.
I watch my run off once every 3-4 days.200 over is the limit anymore and my plants bitch.
Youll catch a problem before the plant shows it,so for most people its a good idea to check runoff.

Ill bet most peoples problems with coco is there not set up with a good way to collect runoff.I always see pots on coasters.Too much work that way and easy to get lazy. Ill get runoff next time ,ya ya.

xtsho said:

100% coco and blumats. 0% runoff. My plants grow just as good as they did before I started using blumats and was watering until runoff.

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I’m running a 60/40 mix coco perlite

myke said:

Must be your nutes as i feed low also.Could be the plants drying up a little too.
I watch my run off once every 3-4 days.200 over is the limit anymore and my plants bitch.
Youll catch a problem before the plant shows it,so for most people its a good idea to check runoff.

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I do run a low feed. The blumat sensors keep the coco at a constant moisture level. There is no runoff which one of the reasons I use them.

I guess liquid nutes run through the blumats just fine? Coco with blumats sounds enticing.

Piper84 said:

I’m running a 60/40 mix coco perlite

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I stopped using perlite a long time ago and now just use straight coco. The only thing I've noticed is that when hand watering you can water less frequently than coco+perlite. You still keep it wet it just stays wet longer. Nothing negative regarding root or plant growth. I hated dealing with perlite and just one less thing to bother with.

xtsho said:

I stopped using perlite a long time ago and now just use straight coco. The only thing I've noticed is that when hand watering you can water less frequently than coco+perlite. You still keep it wet it just stays wet longer. Nothing negative regarding root or plant growth. I hated dealing with perlite and just one less thing to bother with.

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So your doing what people who grow in peat do,your pH is just lower.

GrassBurner said:

I guess liquid nutes run through the blumats just fine? Coco with blumats sounds enticing.

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I use water soluble dry nutes that dissolve clear. Some bottled nutes are kind of sludgy and I wouldn't run any of those as the feeder lines are only 3mm and have the potential to get clogged but with what I call "clean" nutes you won't have that problem. I wouldn't run a gunky nutrient like Botanicare Pure Blend Pro with them. Not that it won't grow decent weed but from my experience in the past it would leave a residue on the bottom and sides of my reservoirs. Same thing with that GH micro.

myke said:

So your doing what people who grow in peat do,your pH is just lower.

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I suppose so. Although don't most people growing in peat grow in a mixture of peat and perlite? Promix which is what many seem to use is premixed with perlite in it.

xtsho said:

I suppose so. Although don't most people growing in peat grow in a mixture of peat and perlite? Promix which is what many seem to use is premixed with perlite in it.

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Yes,but your straight coco wont hold as much water as peat perlite.Ime anyway.