I've used Dr.Tims one and only, saw a lot of success with that product if need be. For future cyclrs. For me, I got marine pure biomedia the large 8x8x4 and the spheres. I've had them in my display tank and sump for a month plus now. Since ill be breaking my display down, I'll be using old water and new along with these biomedias which will have beneficial bacteria for the holding tanks. Good luck.