I will do some extra research and decide which substrate will suit me better, and when that is sorted I will give the swordtails back to the store i bought them from or put them up in one of the fish groups, there's quite a few swordtail keepers in my area and invest in some fish who are more suited to my water, it is a shame because I really like the swordtails and my fish store told me they would be OK in my water parameters, they've been with me almost 6 months now. I was researching flourite black clay gravel last night and seemed like a good choice, however I don't know how something clay based will go and I can't seem to find any reviews or information on it which makes it difficult to know for sure how it works.I used dolomite substrate back in the 1980's but I do not think they still make these. Other members may have options, this is something I did back then and decided it was way too much work, so I have since then only maintained soft water fish.
When I said get rid of the livebearers, I meant maybe a store will take them, or another aquarist. There are lots of lovely soft water fish out there.
Thank you very much for all your advice I really appreciate it and sorry for asking so many questions, even though I've been keeping fish for 3 years you learn something new everyday.