Is it possible to have too much coral in a reef tank? You bet. Certain SPS colonies in my 187 gallon tank have become way too happy, overtaking a lot of real estate in the aquarium. It sure looks pretty having very mature colonies but it can lead to trouble down the road.


The main issue with accelerated growth is that it can restrict flow within the tank. Having strong circulation in a SPS dominant tank is a key ingredient to success since it can help deliver food and nutrients to corals.  Strong circulation will also help to suspend detritus and keep it in the water column, allowing it to be removed via mechanical filtration. Failure to do this can lead to an increase in nutrients and result in problematic algae.

Other Factors

Larger colonies will also inhibit growth of adjacent corals and reduce the amount of light received by corals underneath. Slow Tissue Necrosis (STN) or Rapid Tissue Necrosis (RTN) occurring at the bottom or middle of a large coral is another by-product of quick growth. To rescue a coral with STN one can frag healthy branches or harvest a hefty chunk at the top and re-mount it on a rock.

Ok, so which corals grow rapidly in my tank? One is the Tyree Red Dragon. Boy, years ago I couldn’t keep this coral alive and today it grows like a weed!  Other fast growers in my tank include the ATL Forest Fire Digitata, Tubbs Stellata Monti, Tyree Sunset Monti, Superman Monti and Mystic Sunset Monti. All of these corals, except for the encrusting montis, received a serious haircut the last time I did some trimming 🙂


Tubbs Stellata Montipora


Random Flow

Another thing to consider when you have really good growth is to make sure you have sufficient random flow. Yes, I did hack a lot of corals in my tank to increase circulation but I also added a third Ecotech MP40 to increase random flow, which can help with polyp extension on SPS.


So what is the right amount of flow to have in an SPS dominated tank? Opinions vary on this but I would recommend a flow rate in the range of 40-60 gallons per hour (GPH). This is the number of times per hour that the water volume in the display tank is moved. As an example, a 200 gallon tank with a GPH of 10,000 would have a flow rate of 50X. When in doubt, go with more flow 🙂



Shop SPS Now



If you are interested in purchasing affordable SPS frags that are pest-free and homegrown, you can visit my SPS Frag store.


And if you are looking for additional insights and information, please explore my many other reef tank and SPS related articles as well as my YouTube channel. For an even deeper dive into reef tank care you can check out my Reef Keeping Master Class. This online course is an immersive and one of a kind educational tool designed to help reef aquarium hobbyists build and maintain a beautiful SPS reef tank. The course is a series of video presentations with some supplemental video from my YouTube channel. There are also quizzes to help students retain and understand the information presented in the course.


Finally, for your equipment needs you can visit my online equipment store. We carry a full line of products from GHL, Royal Exclusiv and Pax Bellum.


Happy reef keeping!