Polypnewbie
New member
I have a 20 gallon tank and I am using an underwater power head that is listed for 30/40 gallon tanks. When I first set it up, I was planning on using my tank for just coral. A year ago I added a tuxedo urchin and didn't think about it. But now I'm concerned that the water current is too strong for him. I moved it to the lightest setting but his spines are always blowing around on him and I'm worried it could be too taxing for him.