Welcome to Aquarium Advice!
To edit your profile information or to add your tank specifics in the "myinfo" box, you need to access your profile. Make sure you are logged in, and go to the homepage. In the top right corner, you'll see "Welcome Yodlem" and below that, look for "Update your Profile". Click on that, and you'll be taken to the page to add and edit your info. "My Aquarium Info" is about halfway down the page. Enter your tank information here, and other members will be able to view it by clicking the myinfo button in your posts.