I have a 125g with Africans and my filter is an FX5. Everything is in tip top shape except for the water is pretty soft(GH: 6, KH:4) and my ph could be a bit higher(it's at 7.6). I bought some Caribsea Curshed Coral and have read that you can put some in the filter with pantyhose. How much would you recommend and is there a specific brand of pantyhose to use? Does color matter as far as leeching anything bad? I don't want everything the raise quickly and potentially shock the fish.