The use of dry rock as the primary rock structure in saltwater aquariums has been a very popular trend in the hobby. The rock seems to have nothing but upsides, as it doesn’t have nuisance algae, it lacks hitch hiking pests, and it doesn’t have to be shipped overnight in a bag full of water. Unfortunately, it has one major downside that turns many people off to it. The problem with the rock…phosphate. These dry rocks seem to be loaded down with phosphate in fairly high amounts. Once the rock is in the tank, the phosphate leeches out and fuels insane algae growth, which sort of defeats the purpose of using the rock in the first place. Fortunately, many hobbyists have found solutions to this. For starters, they may soak the rock in RO/DI water for several weeks prior to putting into an aquarium. Other hobbyists soak the rock in an acid bath, which removes some surface layers and takes care of some of the phosphate in the process.