Such a thing as too much flow?

I thought a #2 and #3 Koralia were too much for a 55 gallon, but after adjusting them a bit, they dont' blow around the sand and have greatly reduced the amount of green cyanobacteria algae growing on my sandbed, although the Seachem Phosguard may also be helping. My wife or I will be posting a quick vid on the flow over our new flower-pot coral to have everyone's opinion if there is too much flow on it, and if we should move it somewhere else in the tank.

 

Well the DIY spray bar was fine at the beginning, but then the next morning, the front of the tank had no more sand. So I was thinking instead of asking my parents or older siblings for a ride to exchange for a smaller pump, why not save that gas money and buy a value for around 5 bucks. that way I can control the desired flow from the return lines.