When building a new facility- be it a shed, barn, or warehouse, it is crucial to determine the simplest water storage system solution. This article discusses how you can calculate the size of tank you need and how much water to collect. Here are a few aspects to help you work out what size rainwater tank you need:
  
Roof Harvesting Capacity
 
You should calculate exactly how much water would flow into a tank. That means assessing the size of the catchment surface (or your roof). Bear in mind that each square metre of roof area collects one litre for every one milimetre of rainfall received. Hence, you can determine your tank size by multiplying the roof area by the typical rainfall in your region. For example, if you have a one hundred square-metre roof in an area receiving 10mm of rainfall, you will need a tank size of 1,000L.
 
Water Usage
 
Although every scenario is exceptional, one general rule is to have at least four weeks of water supply. For instance, if you use 1,000L every week, consider getting a 4,000L tank. Alternatively, you can calculate the number of days you do not expect rain. Then, multiply that number by your daily usage of water.
 
One Large Tank versus Smaller Tanks
 
Using one large tank will save space, but it might affect your water supply in case something goes wrong. Typically, having two smaller tanks means you’ll collect an equal amount of water and still have adequate supply if one of them happens to fail.
 
You ought to consider whether to use one giant tank or several small tanks to collect and store rainwater. For instance, if your facility has an inclined roof, you can install one huge tank at one end to collect all the water or put two smaller-sized tanks at every end of the facility.
 
  
The Bottom Line
 
It is important to use the above factors to work out the size of the rainwater tank you need before buying one. Also, since each property and facility is unique, you should talk to your water tank professional to figure out what suits your needs.

Which is suitable for my garden - rainwater or tap water,? If you want your garden to grow and prosper, then rainwater is the best option hand-down.  You can easily capture and store it in a water tank then use it to water your plants rather than resorting using town water. In this article, we are going to cover why rainwater is better than town water for your garden.

Rainwater is as Pure as Water Gets
​Rainwater does not contain chemicals such as chlorine, fluoride and minerals that are often found in municipal tap water. Rainwater also contains less salt, which is much better for plants. These typical town water contaminants are generally not ideal for plants. Just think about it, would you prefer to drink water full of chemicals or pure, chemical-free rainwater?
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Rainwater is Free
Apart from the cost of buying and installing the water tank in the first place, rainwater capture is absolutely free.  Not many things in life are free these days!  Buy every time you turn the town water tap on it’s costing you money in water usage.  If you have a large garden, you will have to use a lot of water over summer and this can really cost you.  In fact, the cost of water continues to increase every year. Who knows what the cost will rise to in 10 years time?  In 10 years your water tank should still be going strong, giving you reliable rainwater storage.

​Rainwater Has Low pH
​Another thing about rainwater is that it has a pH of between 5 and 7, which is perfect for nutrient absorption in plants. But town water genrally has pH that is greater than 7, which can cause nutrient lockout in plants – making it difficult for your plants to absorb nutirnets from the soil . Just like humans, plants also need nutrients and minerals to survive and thrive. If they don’t get this vital nutrient, then they will grow weak and eventually die. According to experts, the ideal PH of water to be used in the garden is between 5 and 7. Anything more than that will limit nutrient uptake.

The worse thing is that even after spending a lot of cash, town water is not the best water for your plants