Help with my first semi hydro

Hi, I'd love to try semi hydro. I have a syngonium currently in water as it was getting gradually more unhappy in soil and it seems to have perked up a fair bit. I have a large clear yogurt pot that I will poke holes in to be the main pot and then planning to put it in a decorative pot as the cache pot. The clear pot sits roughly on the bottom of the decorative pot so am I OK to use this set up and fill ⅓ full of water? I plan to use water from my fish tank, that's what the plant is currently growing in. I havent got the soil (?) yet, I'm unsure between Westland hydroleca (easy to get, cheaper) or Soil Ninja semihydro (harder to get and more expensive), open to other suggestions but my options are limited unless I want to pay horrendous delivery charges. Eventually I'd like to get some frydeks and grow them in semihydro so this is also a bit of a test to learn how to do it properly (frydeks are a wishlist plant). Many thanks!