I started a 29 gallon saltwater aquarium about 5 weeks ago, and got everything I needed, spent alot of time, alot of money, and finally after about three weeks, I got two damsel fish. Everything was fine for about two weeks, I was doing frequent water changes and the fish were fine and eating healthy. Know in the past week, this orangish red stuff started showing up in the tank, I assumed it was algae and just siphoned it out and did some more frequent water changes, but that did nothing! It kept showing up and first my blue damsel died. So I did a large water change and cleaned everything so the problem would not happen again. After spending about 3 hours on this task I thought everything would be fine and the other striped damsel was doing fine. But in just two days everything went bad the algae came back so much in two days all the sand was covered as well as the live rock and sides of the tank, and my striped damsel died of an unknown reason just 15 minutes ago. After this I tested everything about the water and everything was fine. The only thing that seemed to be a problem is the algae or the temperature it fluctuated pretty drastically from about 74-80degrees over the past few days for some reason, is this to blame for the death or something else?? Please help I dont know what else to change and I hate to lose fish, it makes me fell awful. Please give me advice if you can, I would greatly appreciate it!