Possibly.
Back to the original question phosphate removal can hinder chaeto growth but apparently doesn't stop it for long. According to Charles Matthews' experiments the addition of GFO will slow chaetomorpha, but it will eventually adapt and resume growing normally.
Does cheato have to be in a fuge or can it grown in a normal sump compartmentPhosphate binder should NOT affect chaeto growth. See my pic here with my middle chamber OVERFLOWING with chaeto and I use a phosphate binder. Main chaeto requirements for healthy growth:
-good lighting
-high flow
-washing debris free from the chaeto ball
SH