Concrete is very durable and makes a great surface for many different activities. However, it is prone to be stained and can even be damaged, causing pits. If you’re considering putting a concrete floor down or need to have one repaired, then it’s worth looking at epoxy floor coatings. 
These add a layer to the top of your concrete which is much stronger than concrete, hard to stain, and easier to clean. It’s a viable and surprisingly cost-effective solution.  
If you’re set on cleaning concrete, then you’ll find an array of products in your local store that can help you. However, if you prefer to save money then there are two other options worth considering, bleach and vinegar. 
Using Bleach 
Bleach has the advantage of being a whitening agent. In other words, it’s a great option if you need to restore a whiteness or general lightness to your concrete. 
It’s effective and can be brushed into the concrete and washed off. However, bleach is not environmentally friendly. It is likely to kill plants and wildlife in the vicinity. That makes it a poor choice in most situations. 
Vinegar 
The first thing to note is that not all kinds of vinegar are created equal. If you’re planning to clean concrete and you want to protect the environment, you only have one choice. That’s distilled white vinegar.  
You can use the vinegar neat or distil it with water. Your choice will depend on how bad the stain is that you’re trying to remove. Lighter stains can be removed with a fifty/fifty mix of water and distilled white vinegar. 
More serious stains will need a higher concentration of vinegar. As much as just vinegar is fine! 
You should note that while vinegar is good at drawing a stain up and out of the concrete, it will damage the concrete if left on it for too long. It’s best to keep the vinegar on for no longer than 15 minutes. This should create the desired cleaning effect without damaging your concrete. 
Additional Thoughts 
Vinegar is better for the environment and the preferred choice for cleaning concrete as it is cheap and effective. But you should note that vinegar will quickly strip paint from your concrete. You will need to heat the vinegar to get the desired effect and leave it to sit on the paintwork for 15 minutes. You’ll then be able to scrap the paint off.  
Distilled white vinegar is also effective at removing oil from concrete. You’ll just need to mix it equally with soap and water, then sprinkle the stain with sawdust before you apply the vinegar mix. Once the oil has gone you can rinse the vinegar off. It should take no more than thirty minutes.  
Vinegar can also remove mold and algae from your concrete. It’s as easy as putting neat vinegar on the mold or algae and scrubbing the area with a brush. A quick rinse and your concrete will look like new.