I use an Ez-Clone. I had it producing clones for about 8 months without cleaning it or changing the water. I had 90% success. Over time (very slowly) it started taking longer and longer. I eventually realized that something wasn’t right. I took it outside and it had some type of crap ( bacteria?) in it. I rinsed it out and ran 50/50 clorox water through it for 12 hours, then I drained and refilled it with peroxide/water for a few hours, then ran plain water through it for a few hours, then rinsed it repeatedly with tap water. I was pretty sure the manifold was clean but I replaced the pump with a 400gph (brand new) and tried once again. It performed excellent. I believe I had some bad bacteria growing in it that was preventing my clones from developing roots. I believe that being very careful and clean is very important. If any of you guys know the proper terms for what was going on, please let me know…..I got complacent after have 2 surgeries. Please dont spank me!