I searched on both google and here for it but it didnt come up, What is the appropriate water lvl for a tank? I have a 55g long and about how much from the top of the tank should I fill it?
There is no set rule. It is just how you like it to look. Some people like to see the top of the water, so they leave the water 2-3 inches under the trim. Some people don't like to see the water level and fill it to the brim. It also depends your type of filters. If you have a Hang on back filter, then you will hear the water splashing if you leave the water level low. It is all your preference.