At a basic level, solar pool heaters are going to need as much room as the size of your pool dictates. The bigger the pool you have, the more space is going to be needed to be taken up by the solar heaters that you have chosen.
Due to this, it’s important to make the calculations beforehand to see exactly how much power you are going to need to generate. Once you have done that, then you will be able to see if you have enough space to be able to accommodate that amount of power.