Reddish brown algae

What size of tank, pretty tough to get too much flow in a reef tank.

 

Here's my input on flow:

I have a 38 gallon tank with 1200 gallons per hour of flow in it. That's about 31.5 times per hour turnover rate. Not too much flow at all.

So, what do you have for flow in your tank? Size of tank and total gallons per hour of flow (adding up all powerheads, cannister filter, and whatever else you have) is what we're looking for. If it's not at least 20x turnover, then you aren't even close to too much flow.