In August 16 2013 I had to start new with my saltwater. My old tank crack so I had to transfer my old tank to a new tank. I decide to start new I was able to save some of my corals. I change the gravel to live sand. So technically tank is new. In the beginning I did have a bit problem with ammonia but I added bacteria and did water changes and it work. Tank has been doing great! I do 10 % water changes every 2 to 3 weeks. I have 3 fish, purple fire fish, diamond back goby and a six line wrasse. I have live rock and have done polyps. Red mushrooms, hairy mushrooms. I have some hermit crabs and snails and a peppermint shrimp. 2 weeks ago a orange linkia starfish was given to me. I added the start fish and it did ok for the 1st week. Last week tue she didn't look good and I can tell she was dying but was still alive. It died on wed but I wasn't home for 13 hrs so the next morning I found it dead and I remove the remains. But since I'm having problems with my tanks. I had an ammonia spike so 3 days later I did a 10% water change and cleaned the tank. Added the supplements. For 4 days after the water change I keep checking the levels but there was still ammonia so I did 10 % water again 1 week after the 1st water changed. Now it's 3 days after the 2nd water change and the water is cloudy and the levels are off. One of my coral died. Ph 7.4 nitrite is 0.25 ppm
no ammonia. nitrate is 20 ppm
. I work long days so it took me longer to do the water changes. Please I need advice how to fix this. My tank is 28 g nano cube. Help please I need expert advice!