Hello All. Let me apologize. I’ve been lurking in the background, reading posts on R2R for several years now. I’ve learned a lot from the discussions. Thank you all for sharing what you know with newbies like me! I’m not much of a talker…and I don’t feel I’ve gained enough knowledge to help others yet, so I’ve been content to read and learn, until now. I have a few urgent questions I need answers to and I can’t seem to find answers quickly through my own research efforts. I hope you will be able to help. My questions are: 1. Can I use Furan 2 with CopperPower safely? I know many antibiotics can be used with copper, except the sulfur based ones, but I don’t know if Furan 2 is one of the safe antibiotics. 2. After an outbreak of an unknown pathogen or possibly multiple pathogens, should I breakdown my sump that is still circulating my live rock, and a large block and some balls of MarinePure? Should I bleach all sand, rocks, and start over to make sure any pathogen that may not be obligatory (needs a fish as a host) are truly dead and gone forever? Tanks 29Coralife BioCube (reef) with upgraded lighting, large skimmer, and 10gal sump added: Currently cycling after complete breakdown to get rid of a severe outbreak of aiptasia anemones and bryopsis algae. All rock was bleached and new sand added. Ammonia 0, nitrite very high, nitrate readings starting. 29 gal FOWLR with HOB skimmer and 2 HOB filters-one with bio wheel for mechanical filtration: Livestock are 2 very young lightning maroon clowns, 1 yellow clown goby, 1 lizard fish, 1 fairy wrasse, and 1 algae blenny. Temporarily added to tank: 1 coral beauty and one melenarus wrasse. They will be added to one of the larger tanks after treating. Ammonia 0, nitrite 0, nitrate 5-10 with water changes at 20 75gal FOWLR with 15gal sump and oversized skimmer: Livestock: 1 porcupine puffer, 1 yellow tang, 1 Vrolik’s wrasse, trio of lyretailed anthias, 1 engineer goby, 1 flame hawkfish, and two neon wrasses (the n. wrasses were freebies that came with the recently purchased/used 180gal tank - one of the n. wrasses will go into the lightning clown tank or possibly the BioCube as the two neon wrasses do not get along). Note: This tank required frequent water changes before it was turned into a sick tank due to high nitrates (likely because I tend to overfeed). The tank is currently cycling as the sump was taken offline and it contained most of the live rock. There were no problems with ammonia or nitrite before breaking it down to become a sick tank. (I know this sick tank is overstocked but most fish will be moving to the larger 180 gal tank when it is cycled and they are deemed healthy). Some of the fish will remain in the 75gal, though I’m not sure which ones yet. Truly, I’m more concerned about getting everyone healthy right now. 29 sick tank: Currently housing 2 freebies (dot/dash butterfly and an unknown sand sifting goby) that came with the 180gal tank. I recently had to add my o. clownfish and a small majestic angel a few weeks ago to this tank as well. The majestic angel and butterfly (if they make it) are destined for the 180gal tank. The o. clownfish and maybe the freebie goby will be added or returned to the BioCube. The tank is cycling: Water changes every few days…cycle is starting…ammonia 0, nitrites are detectable about every 2-3 days, so 75% to 80% water changes are completed. 20 gal quarantine tank: Currently housing 1 longnose hawkfish, 1 serpent starfish (starfish is another freebie that came with 180 gal tank), 1 pompom crab, 1 porcelain crab, assorted snails and all the coral from the 29BioCube. The o.clownfish and hawkfish belong to the BioCube and will be returned when it is fully cycled. I may add one of the neon wrasses or the unknown sand sifting goby to the BioCube later. This tank has been up and running about 1 and a half years. Ammonia 0, nitrite 0, nitrate 2-5. 10gal water changes every two weeks to keep other parameters in check. As mentioned earlier, I recently purchased and will be setting up my puffer's upgraded home, the 180gal Craig’s List FOWLR with 40gal sump. I should be finished building the stand for it this week and hope to set up it next week to start fishless cycle with ammonia and bacteria boosts. I’m going through salt like crazy! :0. Sashaka P.S. 180gal freebie fish came with ick and CopperPower treatment was initiated in sick tank; newly purchased blue tang from large online distributor added to quarantine tank with newly purchased majestic angel were both observed to be sick after unboxing. What luck I'm having! Tang died two days after unboxing. The rest of quarantine fish were moved to the CopperPower sick tank to be treated with the freebie fish. After 2 weeks, CopperPower was still not working on majestic angel. CopperPower seemed to be working on most fish in 75gal. CP treatment was started in 29gal sick tank, but as wrasses are sensitive to CP treatment, the neon wrasses were moved to 78gal CopperPower tank to continue treatment. What a stupid move!! I just infected the 75gal with whatever is resistant to the copper in the 29gal sick tank! Ugh!! I didn't have another sick tank to setup, so I just wasn't thinking straight.