How do you know all the roots are getting wet with that little water? I feel like the only way I know every root is getting fed is with runoff.
My recommendation for someone that wants to do a thorough watering but not over-water is pretty simple. Someone above mentioned it...can't remember who but it involves knowing the weight of your pot empty. If someone wants to use a digital scale, that works too. But here is my basic technique.
Step 1. Transplant into whatever size pot you are going to use.....but do it when the plant is almost dry. Now you should be adding relatively dry soil when you water.
Step 2. Slowly start watering your plant. Now depending on how big of a pot you are going into will determine what you might need to use to measure the water you put in. For example, in 1 gallon pots I use red solo cups filled to a specific line. If I am using 5 gallon pot, I use 32 oz water bottles. From here, regardless of what size you are using, you start SLOWLY watering that plant. The key is going slowly. You want the plant to absorb it slowly and none going through the pot quickly. Keep track of how many cups you use. Take a short break between cups. Then back again and slowly add more. Keep doing this....adding more (Please keep track of how many cups or bottles you use). When you finally get to where there is just a touch of water starting to run off, you know how much water your empty pot holds.
Step 3. Wait for your pot to almost dry out out. Become familiar with its weight when its in need of watering. I just grab my pot and lift and I can tell in a second or two if I need to water or not. If the pot is heavier than your light feeling then wait a bit. No need to rush it. Now when its ready for another watering, I take my total number of whatever I was keeping track of above (cups or bottles) and I subtract about 25% of one of those units. So in one gallon pots, I can put just short of 5 red solo cups of water into the soil before I have any runoff. Since I am in organic soil, I don't want run off so I do 4.5 cups of water. For 5 gallon pots, I can water with 4.5 32 oz bottles of water. I round that down to 4 bottles of 32 oz of water or 1 gallon.
Many times I split my watering between top and bottom watering so I know everything is nice and watered. Then the biggest key is to leave it alone until the weight gets down to the "need water" weight.
So to recap, start with dry pot.....slowly water until you have just the slightest run off. Calculate your total water used and back off of that total a bit. Presto....now if you wait for your plant to dry out (not to the point of wilted leaves).....you know exactly how much water to give your plant in soil. No more overwatering, no more guessing if you watered enough. Picture perfect every time.
What I like about doing full to empty watering cycles is that I get days between waterings. Smaller pots (1-3 gallons) I get about 2-4 days between waterings depending on how big the plants are in those pots. In larger pots, I tend to get 4-6 days between needing to water.
Now as your plants get bigger and drink more, the time between waterings might decrease. Instead of 5 days, now you might only get 4 days before needing to water again, so keep checking your pot weight as your grow progresses. Don't just assume because it initially was taking you 6 days for your pot to dry out that it will stay at that interval. You might find it drops down to 4 days relatively quickly if she's a big drinker.
