In one sentence, describe what the following article is about: To drain the tank, switch off the water. You can find the valve near the wall behind your toilet. Once the water is switched off, flush your toilet. This should drain all the water from the tank. Look at how dirty your tank is. If it seems relatively clean, all you need is a basic disinfectant. You can use the same spray you normally use in your bathroom. However, with built up debris, you need something stronger. If you notice hardened mineral deposits in the tank, opt for white vinegar. If there is a lot of gunk and mildew built up in the tank, clean it with bleach over a commercial cleaner. With bleach and commercial cleaners, you can spray or pour the cleaners into the tank. Target the bottom and sides of the tank, paying particular attention to areas with built up dirt. Make sure to wear gloves when handling bleach. When dealing with mineral deposits, the process is slightly different. Pour white vinegar into the tank, up to the top of the overflow tube. Let the vinegar sit for 12 hours before flushing the toilet. After 12 hours have passed, flush the toilet and proceed with regular cleaning.
Summary: Drain the tank. Determine the proper type of cleaner. Apply your cleaner accordingly. Let vinegar sit to treat mineral deposits.

In one sentence, describe what the following article is about: Often a rat will scratch a flea infested part of its body more frequently and often quite vigorously. This area can become irritated, red, or inflamed from scratching and from fleas feeding on your rat's skin. Missing patches of fur or red scabs is a good indication that something is irritating your rat's skin even if you don't see them scratching. Fleas like to hide in densely covered areas of animals. If your rat is scratching its armpits and belly a lot more than normal or has irritation in these areas, it might be a sign of fleas or some other skin irritant. Your rat might jump or react violently out of the blue. This is a sign of hypersensitivity to flea bites. If the infestation is heavy, you will be able to spot fleas or its feces. Flea feces or flea dirt will look like coffee grounds on your rat's fur. Use a flea comb or a comb with closely set teeth and run it through your rat's fur. Make sure to run it close to your rat's skin in order to catch and pull any fleas that are hiding under the fur coat. If your comb comes up with any black spots that are dirt-like, it may be fleas or its feces. Have a bowl of soapy water on hand to wash your comb of any fleas you might pull out. Flea feces and dirt can look quite similar, especially if you bring your rat outside to play. One way to tell the difference between the two is to wet any dirt-like specks with water and watch if the spots turn a reddish-brown colour. The red colour is the digested blood that the fleas have ingested which has been broken down by the water. Adult fleas account for about 5% of a flea colony or infestation. The other 95% consist of flea eggs, larvae, and pupae which are harder to see with the naked eye. Check any areas your rat frequents or sleeps, or even areas near or under its cage. You might be able to see flea dirt or fleas in your rat's cage or bedding, especially if the flea infestation is quite heavy.
Summary: Observe if your rat is scratching more than normal. Look for fleas in your rat's skin and fur. Look for fleas in your rat's bedding.

In one sentence, describe what the following article is about: When you visit a stranger's Facebook profile, you may notice that the "Add Friend" button is missing. This is because that person has set their security settings so that they only receive friend requests from people who share at least one mutual friend. You'll need to be friends with at least one person on this person's friends list before you can send a friend request. Many people have their friends list public, allowing you to send friend requests to people on their friends list. You'll see a list of all the person's friends (if their list is public). If the "Friends" tab does not display any friends, you'll have to hope that you eventually make some mutual friends with this person. Look for posts that they comment on and send friend requests to the original poster. Once at least one accepts, you'll be able to send a friend request to the original person. When you view a friend's list of friends, you'll see all of your mutual friends at the top. After you scroll through your mutual friends, you'll see people that have mutual friends with you, sorted by the number of mutual friends you both have. You'll be able to send friend requests to any of these people by tapping or clicking "Add Friend."
Summary:
Add mutual friends if you can't add someone as a friend. Tap or click the "Friends" tab on their profile page. Find people to add. Send friend requests. Add friends from your own friends' lists.