I have few left over stems of staurogyne repens and I planted them in my low tech, medium light dirt tank. They have already gotten used to my water parameters but after 7 weeks, they aren't spreading. Each stem is doing OK but they aren't shooting out side shoots. No CO2 but dosing 2x excel. So, for your staurogyne repens, I am not sure if you would see a nice carpet forming. And I also would doubt that the DHG would thrive in a low tech tank. In m high tech tank, it took me 7 weeks to see them carpeting. High level of CO2, medium high light, and EI dosing. In a low tech tank, they may just grow tall if they manage to survive.