i can get in the back of it, its a bit of a pain being as deep as the back of the tank its set like this from the tank go water goes through the grate at the top of the tank to the filter thats about 3 by 20 inches the heater is offset the filter behind the filter you have a 3 by 20 void for whatever then it goes to the bio balls thats a good 20 by 30 in space then that flows to the carbon tray which is above the pump that runs the tank and the filterd water flows out the bottom inside of the tank here into a big funnel formation back into the main pickup point if i dont do bi-weekly water changes it turns red and purple and green and this is a fish only tank i really dont want algea in mass quantaties help...