I am going to try a trial of Microbacter7 and Reef Bio Fuel on my coldwater tank. I brought it up on my build thread but I thought that it may deserve its own thread. I did my first water change at the 5 week mark. My test results at this point were ammonia 0.1 nitrite 1 and nitrates 20. Not bad I thought and now 2 weeks later I have ammonia 0 nitrite 0 and nitrates 20. I had heard that the combo from Brightwell is supposed to lower nitrates and phosphates and encourage production of bacterio plankton that serves to feed all the filter feeders in my tank. Its indicated for heavily fed and heavily stocked tanks. Check and Check. My tank may put it to the test. I will be dosing as labeled and testing again in two days, and again next saturday. And from then on two days a week until the nitrates are lowered. My interest is whether it works the same on a coldwater system and vodka dosing works so we shall see.