Amongst the complete redesign of the garden I'm having a raised pond (approx 8ft x 6ft x 3ft high). I will be building it and lining the interior with fibreglass for the bespoke finish to our style. However I don't know whether it would be best to use standard bricks or concrete blocks (dense?). The first layer will be sunk into the ground (at least partly).
Can anyone advise what we should use to best avoid any structural issues?