we built an outdoor rip that leads to and from a pond that was like 62`. we did Hagen Fluval Stratum (i think?) on top of fluorite covered with landscaping fabric and more fluorite(mostly to hold it down plus fluorite is great for setting rocks and other such media). It has never had any fertilizer added and its been running for like 5 or 6 years now. Tons of plants growing in and around it!