Today on BRStv, we have another episode of BRS 52 FAQ where we answer all of your frequently asked reefing questions from our popular 52 Weeks of Reefing series. Today we’re answering Yeshwanth Yarremsetty’s question, "Should I keep flow directed towards my rock work, or slightly upwards to create waves on surface?" If at all possible, I’d recommend both. It's important to have surface agitation in the aquarium as this promotes gas exchange. In other words, carbon dioxide is gassed out of the tank resulting in a higher pH from a lower concentration of CO2 and carbonic acid in the aquarium, and potentially lower nitrates as anaerobic bacteria convert nitrate into nitrogen gas that then gasses out of the aquarium. Adequate surface agitation helps to make these processes much more efficient. The other component to this is oxygen entering the aquarium. The rippling surface of the water helps to bring more oxygen into the aquarium. Not only is this important for your corals and fish ability to respire, but it also helps to displace those gasses I mentioned earlier: CO2 and Nitrogen. Additionally, increasing your surface agitation can increase your evaporation rate. If your tank is running warm, a higher evaporation rate is a good thing to shoot for. As the water evaporates it takes heat away from the water. Coupling that with a fan pointed at the water's surface can increase the impact of this effect, and in some cases can drop temps by 2 degrees or more depending on the situation, potentially even eliminating the need for a chiller. So follow along as we answer today's question, provide some helpful insight, and help make reefing just bit more fun and easy for you and your tank. *Legal Stuff* The purpose and content of this video is to provide general information regarding the products and their applications as presented in the video. Aquatic sales solutions, inc. And its officers, directors, employees and agents disclaim all express or implied warranties, in any way, related to the products and their application as presented in this video, make no representation or warranty regarding the products and the application as presented in this video and shall not be liable for any direct or indirect losses or damages of any type, including but not limited to punitive damages, or from personal injury or death resulting from or in any manner related to the video, and the products in and contents of the video. The viewer expressly agrees that aquatic sales solutions, inc. And its officers, directors, employees and agents shall not be liable for any damages or losses related to the products in and content of the video and hereby agrees to hold the foregoing harmless from any such losses or damages.