Nitrites are reading 1.0ppm and Nitrates 20ppm, would a larger water change help lower or should I do something different? I had the same readings the past two weeks.
I’ll assume you’re still cycling - I’d add some additional bacteria and don’t bother testing nitrates again until nitrites start going down, as presence of nitrites will affect the accuracy of the nitrate test.
Nitrites are not important in saltwater like they are in freshwater water. You have no need to test for them. As mentioned their presence can make nitrates read higher than they are. In the absence of ammonia, do a water change and you should be good to go.