Soap residue and clumps of hair can cause a clog in your bathtub drain over time. If you are faced with such a problem, you can first try to clear the stoppage yourself, rather than opting to call on the expensive emergency plumbing service right away. Here are some methods that you can use:

Using Baking Soda

Remove the strainer or stopper by loosening any screws that secure it. You would find that there will be gunk accumulating underneath the component, so you should clean it.
Boil water in a tea kettle. Then, pour the hot water directly into the drain, which might immediately unclog the drain. Now, turn on the bathtub to see if the clog is gone.
Pour ¼ up of baking soda into the drain and follow it up with a cup of white vinegar. Wait for about 15 to 20 minutes to allow the mixture work its magic in loosening the clog.
Boil more water in the kettle and, once again, pour hot water directly down your bathtub drain. This time, the water will react with baking soda and vinegar mixture to get rid of the clog. Test your bathtub to see if this technique has unclogged your drain.

Note: Using baking soda and vinegar does not require any chemicals and generally works for smaller clogs, which means that it does not work every time.

Using Chemical Drain Cleaners

Purchase a chemical drain cleaner from your local hardware store. This solution is formulated to unclog drains with chemicals, such as sulfuric acid or potassium hydroxide. When choosing a cleaner, make sure that it is designed for your bathtub’s system, considering the type of pipe used in it and other important drain components.
Read the manufacturer’s instructions on the back of the cleaner, as this information can differ from one maker to another. But usually, using this product will require you to wear protective gloves and goggles and use only the recommended amount of liquid. This is to ensure the effectiveness of the product as well as your safety.
Remove any standing water from your bathtub, which means that you might need to use a large cup or a bucket to do it quickly.
Pour in the recommended amount of cleaner to your bathtub drain. Make sure you will not splash any of it as you open the bottle because it can cause burns. If there are any spills, clean them up immediately and wear gloves at all times.
As your bathtub drain cleaner most probably instruct, let the chemicals sit in the drain for about 15 to 30 minutes before flushing it with cold water. Your drain should be working after this. See if water immediately disappears down the drain after you turn on the faucet in your bathtub.

Using a Toilet Plunger

Scrub the stopper or strainer to remove any gunk, hair and soap scum. You can remove the stopper or strainer by loosening any screws that secure such components, twisting and lifting them.
Fill your tub with a few inches of water to a level that the plunger is submerged. Take note that water can greatly help the plunger get enough suction to get rid of any obstructions in the drain.
Place the bowl of the plunger over the drain, and then press and pull it at a rapid pace. This task will require you to exert some force, so be careful not to get splashed on. Most likely, you will see dirty water with gunk rushing out of the drain, while you are plunging.
After about several plunges, and you do not see dirty water and gunk coming out, try putting in more force. Keep plunging until you see the water draining down the pipe when you remove the plunger.

Using a Drain Claw

Remove the strainer, and as mentioned above, you would find hair and soap gunk accumulating underneath it. Clean it up by brushing or any means possible. If your drain has a stopper, instead of a strainer, remove it. This can be easier to do because they are not held down with any screws. You can just twist and lift it by hand. And again, remove excessive gunk around it, which have accumulated in the area over time. You may have to scrub it, depending on how dirty it is.
Insert the drain claw down the drain deep enough that it is going to hit the trap, which is the curved part of the drain. Keep pushing the claw through this area, and do not worry about breaking something as this device is very flexible. It has many small interlocking hooks, so you should be able to grab and pull out some hair and other debris that might be causing the clog.
Pull out the drain claw and clean the gunk that it has pulled out. Test the tub to see if it is unclogged. Turn on the faucet to see if water is now going down the drain properly.
Replace the strainer or stopper in a reverse manner that you removed them. Remember that strainers need to be screwed back onto the top of the drain, while stoppers can just be placed back in the drain by hand.
Keep the drain claw to be used again in the future. Keep in mind that hair and soap scum can build up in a few months, so having this device comes in handy at times.

Tips on Preventing Clogs in Your Bathtub Drain

Preventing the occurrence a clogged bathtub drain requires only a little work. To avoid spending excessive time, effort and even money whenever this problem happens, you can make it a habit of pouring down hot water into the drain on a regular basis. This will help loosen any fresh gunk that would build up over time.

If you have tried all these methods and nothing worked, then it would be best to hire a professional to get the job done for you.