If you are using manure tea to amend the soil in your there are a couple of different ways that you can use it.
Directly in the reservoir container. If you made your self-watering containers with the pipe, you can pour the manure tea into the pipe as you would normally water. If you aren’t using the pipe, then you can remove the planting container and pour the manure tea directly into the reservoir container.
When you are done watering, sprinkle some of the manure tea on top of the planting container and allow the self-watering container to do it’s thing.
Pour on top of the soil. You could also use the manure tea by watering the container from the top like you would normally water. The tea will eventually filter it’s way down to the reservoir container where it will be stored.
Either one of these methods is fine to use. I’ve been using the manure tea about once a month.
Are there any other ways that you could apply the tea?
I imagine you could also use it as a foliar feed. That is how I typically apply fish and seaweed stuff.
Yes you can. Good call on that.