Hello, Thanks for taking the time to read this post. Here is what's happening... I just set up a 24 gallon tank (nano cube) and have had a high sucess rate untill my 1st Water change last night. I came back to find 3 of my peices dead (Yellow Tang, Clown Trigger, Boxer Shirmp) and the ones left are pretty stressed out. It has been about a month and a half since I started my mini reef and as recommended I changed out 20-25% of the water and replaced it with salt water from my local fish store. I did my best to take the necessary precautions. Matching the water temperature (80º), rinsing the filter out with disposed water from the tank, added the new water slowly (though I probably could have done it slower), added live nitrifying bacteria and oxy-boost. Does any one out there know what could be a possibly cause for this and what I should try to avoid in the future? Obviously, I am not going to be getting my salt water from that store anymore. That's for sure. But if you could let me know if there are any tricks to water changes. How often? How much water? Anything at this point would help. My goal is to have a nice little mini reef. I hope! Here is what I currently have in my 24 gallon tank. 10lbs. live rock 1 clown fish 1 damsel 1 serpent star fish ( who has oddly climbed to the very top of the tank, trying to get close to the filtration intake) 3 Snails ( nothing fancy) 1 rock crab Like I said, I would appreciate any help I can get with this. The thought of killing these little guys isn't a fun one and I want to do everything I can in the future to avoid it. Thanks so much.