ok, the cories i have are 2 bronze cories. the water parameters are from just before my water change, i test just before i change the water to see what it gets to at its worst, so its 6 days worth,plus the last time i did a pwc it was only about 50% as i had to go out,and i also overfeed,i feed them like 3 times a day sometimes,hence the jumbo water changes lol. most of the time it tests at around 10-15 nitrates before water change time. my filter is a tall black one which sits inside the tank,it says fluval 4+ on it,there is quite a strong current in the tank, which uproots 1 of the smaller fake plants every couple of days, but it keeps the fish moving around nicely and they also have plenty of resting places too out of the current which some of them use. im not sure about adding any more cories,the 2 i have seem very happy and active, and i dont want to risk disease by over stocking. its a hectic looking tank,with tons of movement and colour, exactly what i wanted. i will try to get some pics of it and post them up on here, just have to find my camera coz my phone cameras rubbish lol! think ive answered everyones questions!