I keep getting conflicting suggestions on how to water. I am using roots organic + 25℅ growstones. Center Solo cup sized light warrior for seedling.
At first I watered lightly and used the knuckle check. When they got about their 4th set, I watered to 10℅ runoff. 4 days later she was dieing from lack of water though she was 8' high and a bushy 10" wide at 20 days. She perked up after watering to 20℅ runoff.
Now my issue.
Some say to weigh the pot to see when it needs water. That could get old quickly with 6x 5-gal pots.
Some say to water it every day since it is hard to over water fabric pots. Couldn't that stress them?
Others say, since after 4 days they drooped, water after 3 and water more often as it gets bigger.
Has someone done autos starting in 5 gal fabric pots with soil?
The logic of gauging soil moisture level by run-off is entirely flawed.
For example, go dry some potting mix right out. Completely
bone dry. Now pour water into the pot. What will happen? 99% run-off. Why? Because it's really wet? No- because it's really dry. Potting mix will
repel water when it's dry. This can actually make re-wetting a very dried out pot difficult. On a side note if you even need to do this, it can help to actually put the pot in a larger (sealed) bucked of water, so when the water runs out of your pot it will still be submerged. You may actually find your pot
floats when you do this. It can actually take an hour or longer for the pot to stop floating/re-wet fully.
The only reason you should care about run-off is a rough gauge of knowing your soil is being flushed through (to avoid salt build up from fertilizers). However from the above information, you can gather that it's not an accurate measure if the soil is dry at the time.
There is no easy way to tell when your soil is wet enough. A lot of it you will need to learn by feel and intuition, based on knowing the thirst level of your plants, the behavior of your soil, knowing when you last watered, etc. It can be helpful though to just stick your finger into it (if you can, though you often can't in late stages with lots of roots and soil compaction, etc). You need to be aware that the surface will appear dryer than just below. This may actually be part of how you gauge the water level though, along with other details. You may use a system where you see the surface look dry and then wait until the next day, or etc.
To add a little more to the 'go by feel/intuition', try to learn the thirsty periods of your plant life cycle. In the mid to late flowering period, they can go from watering maybe every 2-3 days to every single day or it will wilt. Don't use that example as an exact recipe though; as it will come down to the size of your plants, size of your pots, composition of your soil (such as how much perlite or other aeration, etc).
If you can, watch the plants like a hawk. The leafs will tell you when they are a little or very thirsty. If you get it wrong one day and see a bit of sag, adjust your feel/intuition to try to get it right over the next week (and make note about the life cycle period you are in for the next grow).
One last thing I will add: weed is very thirsty. You are more likely to dehydrate it than drown it. As long as your soil has a good aeration component (so is not just 100% peat or something) then it will be less harmful to go over the top with water than to withhold it.