Most Frontosa fry now are mostly captive breed. I would QT them and watch for ich the most common disease in this hobby. Also, try to keep them all together in same tank rather then split them up, they will happier with large group and they are extremely slow grower. I would remove the pleco since it's a pooping machine and down grade your water constantly and not benefit to Frontosa fry. Some folks will say large (50%~75%) water change is bad for frontosa but I would say it's not true since most fry are now captive breed so they are somewhat adapted to our modern world life style
I"m doing 50%~75% water change per week to keep nitrate below 40 ppm and ny fronts are happy with the WC schedule.