Hi, I’m still having issues in my smaller tank with white spot and now what looks like fin rot. I’ve lost 4 guppies and 3 L183 plecs. There’s no ammonia and nitrite and the nitrate is around 40ppm. I’ve stopped using esha 2000 and exit as it never made much difference. The temperature is around 26 degrees c and PH is around 7.2 Any help would be appreciated.