Bob, Thanks for your response to a long e-mail. I’ve done some research on the site and I’ve arrived at a 50% solution and was hoping for your advice on the other parts. Per my prior e-mail, my current sump is a 55gal that is broken up into 3 sections: skimmer and heaters 15″ — baffles 17″ high — return section 17″ long — baffles 16″ high — refugium 12 long; where the downspout is split into the 2 end sections (slow flow into refugium, about 50-75GPH). It makes sense that a 12×12 DSB will add value, but probably isn’t enough. Here was my thought: Regular 1″ sand bed in main tank. Add a 24″ long true refugium (no baffles, entire tank just refugium). Have the water enter from the downspout (still split for slow water flow in the refugium) on the main tank and then have the outflow gravity feed into the sump. This 24″ long (12 wide) section will have a DSB of sugar fine sand, LR, and Macroalgae, 1 or 2 types (unless that is a bad idea).
