New Clownfish- stringy white poops

[CARBON]

So, I purchased 2 clownfish (about 1" long) on April 2nd and I put them into QT. I dosed Prazipro for a week and started cupramine treatment yesterday. However one or both are still occasionally having white stringy poops. Both have very healthy appetites and I feed New Life Spectrum thera twice a day. Should I redose prazipro after my 2 weeks of Cupramine or is this normal? Thanks!