Why did my Chinese Algae Eater die!?

Look and see if his gills are moving, but I can pretty much ure you that if he's not dead, he will die soon. Once fish are to the point of not being able to swim, they will not recover. Okay, there is a lot to know about fish keeping and you obviously are a newby :-) The tank being to clean is the reason the fish died... when you start a fish tank, it goes through a process called "Cycling". Simply put, fish need certain bacteria in the tank in order for there waist to go from toxic chemicals to not toxic. "Cycling" is the process of establishing these bacteria colony's in the gravel, the filter and all over inside the tank. When a tank cycles, it goes through 3 chemical spikes, ammonia, nitrate and nitrite. This process takes about a month to complete. You have already started this process by adding fish. The fish probably dies because you are having a spike, most likely the ammonia spike. So, you will need to get a test kit so you can keep track of where you are in the cycle. Once you start having spikes (which I'm sure you already are) you will need to do a 20% water change every day. When you have had all 3 spikes and everything is at 0, do a 50% water change. The day after that, test your water again and if everything is low, the cycle is over and as long as you NEVER take out the gravel or take out to much water, you won't have to ever worry about it again for the life of your tank. There is a lot to understanding cycling, so search "aquarium cycling" if you really wanna know all about it because what I just told you is really just a very short summery of what's really going on. A few other things that are important for you to know to keep all your fish alive and healthy - when doing water changes, always add the water conditioner before you put the water in the tank. Also always make sure the new water is the same temperature as the water already in the tank. If you don't have a heater and a filter, get them because the fish will never be healthy or live long without both. If you can only afford to buy one at this time, get the filter because it is the most important piece of equipment in your tank. Try to avoid buying fish from any retail stores such as petsmart, petco and walmart, there fish are often inbred and in poor health making your odds of keeping them healthy even lower, try to find a store that specializes in just fish, there fish are usually much higher quality and healthier. Never clean a fish tank, after the cycle is over, just do a 20-50% water change once a week and your fish will be happy and healthy. I hope all this helps and if you have any more questions just keep them coming or feel free to email me personally if you ever need help :-)