Fishface I'm easily confused too so glad that cathie and ella have explained the pozzani because if i'd have tried you'd be more confused than ever , I'll let you know if the seachem matrix makes any difference, so far ive had it in the filter for approx 3 weeks and there isnt much of a change to the nitrates i manage to keep it at 30ppm by doing 2 water changes a week.

What's seachem matrix then Lisa ?

I have heard of it, but not only am I easilly baffled, but I am getting a bit forgetfull

Sounds like an essential bit of kit if you have high nitrates in your tap water.
I moved from an area with zero nitrates in the water to an area having around 15ppm nitrates. That was a bit of a shock to the system. Would hate to have nitrates as high as your tap water cathie

http://www.seachem.com/Products/product_pages/Matrix.html

put a link that will explain better than i can but its supposed to help to convert nitrate as well as ammonia and nitrite.

Sounds interesting Lisa, let me know what you think of it - does it work