thats what im finding out LOL! i thought it was gonna be hard, but it doesnt seem to be too difficult. From what i have read, brackish fish might be a bit easier to maintain, simply because since they naturally live in areas where the water parameters fluctuate, they dont have to have perfect water parameters, it is ok if it is allowed to fluctuate a little bit. but, you have to measure the specific gravity, using a hydrometer. if you wanna set up a BW tank though, make sure you find a hydrometer that measures low-salinity, and not just salt water. you will prob pay double the price for a brackish-full marine hydrometer, than just one that measures marine water. when you do water changes you take a bucket or whatever, let the salt dissolve a bit, then pour it into the tank. So far so good lol. seems alot easier than my angelfish/discus tank