Find tank water level and capacity

In this video ‘find tank water level and capacity’ I demonstrate an easy low tech way to find the level of water in a garden tank by using a hose pipe. I also show how to estimate the amount of rainfall, in mm, that is needed to fall on a shed roof for the run off to fill the tank using first an empirical or practical method and then a theoretical method. Both methods of calculation arrive at the same answer.

Step 1. Attach a hose pipe to the tank outlet

Step 2. On the outside of the tank, start above the tank over-flow holding the hose pipe vertically with the opening pointing upwards.

Step 3. Slowly move the hose pipe downwards until water just starts flowing out the end, this point will represent the water level inside the tank.

Step 4. Using a whiteboard temporary marker draw a line to indicate the water level and write the date.

Step 5. Do not use any water until after your next rainfall then note the amount of rain that fell and re-estimate the new water level as above. Measure the distance between the 2 marks in cms (call this figure ‘a’). Then divide this distance into the total height of the tank in cms (call this figure ‘b’). Now multiple the answer by the number mm of rain it took to lift the water level to the second reading (call this ‘c’), this will give the total number of mm of rainfall needed to fill the tank completely Call this’d’). Here is the formula: d=(b/a)*c. This represents to practical or empirical method. For the theoretical it is best to watch the second part of the video.

Here are 2 more videos demonstrating different methods to find the level and capacity of a garden water tank:

Here is the video demonstration:

Here are some time stamps for browsing the content of this video:

00:00 Beginning

00:45 Gravity feed garden tank outlet set-up

01:20 finding the tank water level with a hose pipe

01:58 Marking and recording water level

02:20 Practical calculation of mm rainfall needed to fill tank

03:51 Theoretical calculation of mm of rainfall to fill a garden tank

Here is a link to the blog article:

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