Runoff! How exactly do I make it happen?

Hey all, I did a search on the topic and plenty of discussions on post run-off measurements, but not much I found on the actual process and why its important. I figured this could be a great tuturioal for the newbies like myself, who prior to this run didn’t know what ppm/tds or EC meant much less why its important.

So perhaps the experts, or anyone with runoff experience, can chime in on how they go about it. And when you water, do you have a rough formula based on your medium and size of container (understanding that different stages the plant might eat differently) telling you how much water/nutes to mix? Like, 1/4 gal of water per gal of soil? Making that one up but might not be far off.

In my example, I have 5 gal fabric pots. The one time I got significant runoff, I think was due to watering too fast and that water leaking through the sides of the pot, not through the bottom. Ive also fed a very slow, methodical process where I slowly water a bit, move on to another plant, then return. I did this 6 times yesterday with 4.5 gallons of water for 5 plants. No runoff.

So, either I’m too slow, or its not enough water. But for myself, and other newbies, this might be a valuable topic on the actually process, then we can talk about results.

Thanks in advance to all who chime in! And if I missed a thread on the how to, please let me know. Take care.

This is from my limited experience with pots, and soil

I wonder about fabric pots too…?
I also wonder about other mediums like coco or hydro do you ever flush?

With all the other pots water like OP described and keep doing it until water comes out, measure the water in the plate under your pot.

Mind you…

If your plant is still young this can cause some significant stress…

If you have issues with the soil better repot into good soil.

Don’t flush until her roots have colonized the whole pot.

With proper soil you won’t run into issues until the pot is well colonized by roots.

That’s my two cents…

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If you are growing in soil, I wouldn’t worry too much about PPM or EC readings. Soil has lots of
goodies in the soil. Vitamins, microbes and secondary nutrients you can’t account for. Focus on
PH of your soil and maintain that PH balance. If you are growing in coco, rockwool, Hydro or any other method besides soil, THAT’S when you want to look at PPM, EC and TDS readings.

In order to get run off, you need to throw as much water as needed to completely saturate the
soil. Now remember, cannabis likes to dry out between waterings so you might only need to
water once a week until your plants get to a size where they are consuming all the water you
you’re throwing at them and you need to now water 2 times a week.

Feeding schedules depend on two things, what medium you are growing in and what nutrients you are using. Dyna-Grow will be completely different from Jacks 123 or Fox farms Trio. You also have to take into account if you are using HOT soil (soil that comes with vitamins already in the dirt) you don’t want to feed your plants until you deplete the nutes in
your soil through the grow. Usually 5-8 weeks if you are using Fox Farms Ocean Forrest or Happy Frog before you give your plants ANY feedings with vitamins.

If you are growing in soil, remember that there are microbes within that soil that aid and benefit your plants so letting the soil dry out too much will kill off the healthy colonies of beneficial bacteria and fungus so finding a balance between wet and dry is something you’ll have to work on.

Lastly: Lots of pros and people with WAY more experience than me DO worry about PPM/TDS and EC when growing in soil. Growing to them is like second nature and they have
it down to a science. On the other hand, I’m a noob and I’m still learning the ropes, what works and what doesn’t work. The information can be overwhelming at times but it doesn’t have to be. Watch your plants closely. Let them tell you what they need. Don’t swamp yourself
with arbitrary info that is meant to perfect a grow rather than just be successful. Keep an eye
on soil PH and soil moisture for a decent and hard earned crop and ignore the rest until growing feels more natural to you.


Couldn’t agree more…

and knowing about these “non” issues with soil gave me some relief…

You still can flush… if you overfed a flush might be helpful.

Still never rush a flush…

Like i did thinking i saw some claws snd nitrogen toxicit, she isn’t happy about it… All droopy… She’ll be better off tomorrow though…


get yourself a 7/16 or 3/8 rod or metal skewer. Before you water run the skewer down into the soil to break the hydrophobic pockets up and allow water to penetrate down to the bottom.
(Avoid getting too close to the stem and root ball center because you don’t want to hurt the
taproot. 3 inches out from the stem center is a good place to start)

Appreciate this, and all the things you mention (FFOF being hot, don’t use nutes initially) I have learned along the way, luckily not making a big enough mistake to hurt the plants long term.

That being said, things look good and nearing the 1/2 point, I want to dial things in so the PPM readouts are important to me based on research - helping avoid ph bomb due to salt build up, nute lockout, and also as I increase the intensity of my lights so to must I increase my nute ratios. PPM helps guide my hand and honestly, I like to geek out a bit on the science. Like you stated, PH is def something to focus on first.

I believe the compost tea I use helps with those microbes, which is another reason im looking for the PPM. Now I do a nute feed then my next is water with sugars and calmag, and top with some of that compost tea. I don’t know if the plant is getting too much or little of nutes, so Im trying to rely on PPM.

But my initial question was how the hell do I get runoff and I think it was answered. Like many things in gardening, it jus depends :slight_smile:

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Just throw as much water at them as they will take until the plants pee themselves out the
bottom edge of your pots. In 5 Gal containers, I hope you have a place to PH correct LOTS of
water. Or you could do them one at a time until you get the runoff you need.

I’m growing in 3 gal pots and it takes me 1 gallon of water to get a respectable amount of runoff.


I may have read a post by you with that amount, I figured if your 3/1, I would be at least 5/1.5.

So with 5 plants, that’s 7.5 gals to PH. Your right, I only have a 5 gal bucket lol.

Do yourself a favor and break up the task. Don’t do all your plants at once. Do one on Monday,
the following plant on Tuesday. the next etc etc .

Sitting watching plants grow is probably the most painful aspect of growing. So break up your
chores and give yourself something to do for them each and every day. It certainly helps the time go by faster.