Slice carrots into chips or sticks, it is personal preference. Slice onion and Jalapenos.

Fill large Mason jars with the vegetables.

Mix Salt with the water to create a brine. Pour into jars and fill to 1 inch below top.

You must weigh down the vegetables so they don't float to the surface. I use glass weights. As long as it isn't metal.

Now myself, I use air lock lids which are fantastic (purchased mine online). Another option is to use a small ziploc bag. Push bag into the neck of the jar and fill bag with water to the top of jar. This will allow the CO2 to escape from jar and keep air from contacting the vegetables.

Allow vegetables to ferment for 7 days in a dark corner of your kitchen. Afterwards you can place lid on and put in fridge. The longer it ferments the better it is, I like mine to ferment for 10 days. You will see it start to bubble after the second day.