HELP new to being a pool owner

[daisy22]

hello
we're really glad we've found this forum.

our pool has only been in the garden for about 3 weeks but it has hardly been used due to bad weather. i.e. no sun.

it was a lovely blue colour at first, but now it has turned a light greeny colour. what should we do?

Also, the measurements of the pool are 24' x 12' x 4', how do we calculate the litres of water that it contains? How many chlorine tablets should we use? How often should the pump run?

Really sorry for all the questions, hope someone can help.