Ulva intestinalis is easy to grow, fast growing, does not fragment as much as Cheato, hardy and can be grown in the sump or in an algae scrubber as I grow it. If any should find it's way into the DT most algae eating fish will soon devour it. I put some in my Gourmet grazer and most my fish love to eat it so we also get free food. In a few short weeks. With regards to results, I have seen my tanks NO3 drop from 25ppm to just 2ppm. Ulva intestinalis is found in just about all the oceans of the world from tropical to temperate seas. This algae is quite possibly the best algae to grow to reduce NO3. if there is a better algae for our needs then I have yet to encounter it. :: Algaebase 7 days growth in my ATS 300 grammes. Yes, this much Ulva growth in just 7 days. This is how hard I trim the algae back off the screen each week.