I have a wet dry measurements are 17 high, 24 long, and 10 wide. Should fit in your 55 stand and this wet dry will inlude bioballs and has a pull out drawer to place a filter to catch the waste before going into the bio ball chamber. This wet dry is rated for a 125 gallon tank. /i do not have a overflow box to include, I am using it, I will sell for $75 and you pay shipping. In great shape, I only used a short time.