I have just upgarded from 25L tank to 250L tank.Now for my 25L tank I changed about half the tank water every week. Since I have got a bigger tank can anyone tell me after how long and how much water change is needed for a 250L tank. I have about 20 neons, 2 suckers, 1 female betta, 8 other neon sized fish (dont know the names). It has Aqua One 1000 filter on it.Also do I need to run the filter 24 hours , currently I am switching it off at night, so it runs 6 hours.I alo turn the tanks lights off at night. Please guide me.