Around this time, I generally start having a nice bubbly starter with a pleasant, yeasty smell. However, everyone's conditions are different, so don't worry if you're not there yet! Just continue with feedings. If your starter smells good at this point and has good bubbles, you can start using the discard for sourdough discard recipes. Once you start seeing good bubbles and having a pleasant smell, which is usually sometime during the second week, increase your feedings to 100% hydration with 100g of flour.
100% hydration feeding means a 1:1:1 ratio of starter:flour:water. This can vary slightly based on the absorbency of your flour, but it will be about equal. For my brown rice flour starter, it ends up being pretty even, but with my sorghum starter, I find I only need about 80g of sorghum flour to 100g each of starter and water. We're looking for a thick, pasty consistency, so add a little extra water if your starter gets too thick.
Once you switch to the 100% hydration feeding, you will start seeing good growth and should notice that your starter will double (or come close) sometime between three to five hours after feeding. When it's at its highest, that's what we call peak activity. Peak activity is when you'll want to mix up your preferment for your sourdough bread.
Starter Maintenance
Where to store your starter: I store mine on the counter and it does well. In cooler climates, some people prefer to keep it in a warm area, such as on a fireplace mantle, the microwave, or in an oven with the oven light on. If you choose to risk it with the oven, I recommend place a post-it note over the "on" button so you don't preheat your oven with the starter in it! Once established, you can store your starter in the refrigerator.
Regular Feeding Instructions: if your starter is at room temperature, you will want to feed it every day so it doesn't get too "hungry" and create a lot of "hooch", the alcoholic liquid that can form on top of a hungry starter. You will continue with the 100% hydration feedings, meaning you will discard down to 100g of starter every day, and feed it with 100g room temperature filtered water and 80-100g gluten-free whole grain flour. Mix well and cover lightly.
If you are storing your starter in the refrigerator: you will only need to feed once a week, following the same instructions as above.
If you are feeding for maintenance: you can feed and return straight to the refrigerator.
If you are feeding to prepare for a bake: remove from the refrigerator, feed as normal, and make your preferment when the starter is at peak rise. Sometimes, two feedings are needed to help the starter come back from its dormancy in the fridge and get to a good, bubbly rise.