Do we consolidate product pages that are variants from each other?

We have products with different sizes and they each have their own page with very similar content. Ie. Pure Water 500ml and Pure Water 1L.

We are ranking no 1 for Pure Water 1L, but we are not ranking well for "Pure Water", which has a 5x higher search volume.

Should we just consolidate the two product pages to "Pure Water" and mention 500ml and 1L on that particular page so they all lead to that page instead? Or remain as it is and try getting to rank one of them for "Pure Water" as wel by using proper anchor text when internal linking?