i have a pair of macmasteris and two small kribs(1 inch)in a 20g tank.my ph is around 7.6,dont have the other stats.theyve been in there for about a week.i have a ugf,and a 10-30g hob filters running.ive done one 40% water change yesterday.all that ive read says my ph has to be lower,and to soften the water.they have already showed a little prespawn behavior,sharing caves ,getting closer,she flaring at him a little.my questions are,what is the most efficient ways to lower ph and soften water??(never did it before)and will she change color or any other positive signs of spawning???