If the frags are colorful and growing, then don't worry about PE.
I echo the sentiment to do a few water changes, if you have not. The ugly phases can use up some of the elements. Water change offers the best reset button.
You can have too much flow, but most people do not.
Check again for pests. Everybody's first response is to say that they do not have any, but you really need to look hard. Bottom side with a strong light is the best way. Look for bugs or bite marks from AEFW - google has tons of images on both.
I echo the sentiment to do a few water changes, if you have not. The ugly phases can use up some of the elements. Water change offers the best reset button.
You can have too much flow, but most people do not.
Check again for pests. Everybody's first response is to say that they do not have any, but you really need to look hard. Bottom side with a strong light is the best way. Look for bugs or bite marks from AEFW - google has tons of images on both.