Watering

[Jacare]

Ok guys as mentioned in other thread's I'm hoping to get my new grow going maybe next week.
I want to make sure everything is dialed in down to the basic stuff like watering.
It will be an auto in a 5 gal pot. What I want advice on is measurements. How much SHOULD I be watering? Frequency isn't an issue but I want to nail the amount. I've seen plenty of people say until 20% run off. All due respect I can't tell 20% by eye.
So is there something I can refer to as a guide to or could I get some advice please?

Thanks.

 

[Ennui]

I'll preface that I'm in my first grow, but I have learned and observed a bit about watering as applied to a real scenario.

Are you sure you aren't mixing instructions for soilless with soil? From what I've read, soil doesn't require the same as say coco. In soil, a lot of waste is handled by microbes and neutralization by other elements in the soil. In soilless, you depend on the flush to remove it. Sure, a little extra help via some runoff each time can only be a good thing, but you could be washing nutes through the soil before they have a chance to be utilized or broken down for use if overdone.

The best advice I could give you is not go by anything you've read as to frequency or amount and go by what's in your garden. If the pot feels light and the top inch of soil is dry give it some water. If not, don't. Too many factors to be able to say one size fits all. Also, with any pot, as soil dries it shrinks away from the sides of the pot. Water, like electricity, will take the path of least resistance, so most of it could end up down the drain without ever seeing a root. Plastic will overflow the bottom well and cloth will leak like a sieve before soaking in. You could dump 10 gallons on it and not accomplish a thing.

With soil, you have to be very careful with nutes. A lot of it comes premixed with enough to last a month or two, depending. Adding more could do more harm than good. I had Nitrogen burn when I added an 1/8 dose of the most dilute recommendation too early on one plant. That's the only time I flushed. I slowly put 3 gallons through it so it would soak through instead of run around and a day later it was chugging, all wounds healed. That's a reason to flush soil, along with the nute flush just before harvest.

Don't listen to anything other than your plant in your garden. Trust your senses. If I had stuck to a schedule I'd be having issues now instead of smooth sailing into flower. You've got an auto, so you have one, limited chance to get it right. I'd be erring on the side of caution, you can always add but taking away can be a bear.

So, IMHO, with soil only flush if there's an issue or you're heading to harvest. If you really can't control the OCD we all come down with as soon as we sow a seed, give it a flush right before flower to 'clear the slate' if it makes you feel better.