Which corals are dangerous to one another?

[EntitledSushi]

Looking on-line I see many photos of reef tanks absolutely full of corals, with no virtually space in between them. At the same time, I have read many posts that say corals fight and sting one another, so you need to be very careful to space them apart. How can I reconcile these two pictures? Is there a short list of dangerous (to each other) corals that are best avoided?

 

[Webslinger]

they all fight for space. If not they would all be intertwined.

 

[Billdogg]

All the different species will fight for a space of their own. That's how they grow. That being said, they do it in many different ways. Soft corals release turpines into the water that irritate stony corals (alleopathy). That can be mitigated with good skimming and the use of carbon to filter it out. Many stony corals will extend sweeper tentacles to sting other encroaching stonies. Some succeed just by growing faster than surrounding corals.

The key to a successful reef system is to research what the different corals do and how they react, and plan accordingly.

This is a photo from the left side of my mostly SPS 120 DT. You can see how the different corals are growing into/around/next toeach other. I prefer to allow them to figure things out on their own. IMHO, it looks so very much more natural that way. Winners? Sure. Losers? Yup, them too.

This is a montipora that just plain outgrew the tank. I removed it to allow for more variety. It was too big to fit in a 5g bucket so I put it in a large cooler to take to my LFS for a little store credit!

 

[muzikalmatt]

The general rule of thumb is that if they are the same specific species they won't fight each other (but I don't think that's 100% always true). For example: different types of frogspawns or hammer corals can be placed next to each other and won't fight. Similarly you can put most zoanthids next to each other and while some may outgrow/overgrow the others, they likely won't kill each other. That's why you tend to see specific coral "gardens" like zoa gardens, ricordea mushroom gardens, etc.

That said, you really just need to keep an eye on your tank and watch for coral warfare. With LPS corals as well as chalices, you also need to watch your tank at night after lights out to look for sweeper tentacles. I have a large brain coral that puts out 6" sweepers that stung many neighboring corals until I moved them away. Just this morning I had to move my new frogspawn frag as it was stinging my fungia plate coral. I moved the frogspawn once yesterday and overnight the plate coral moved closer to it (trying to pick a fight it's going to lose). So I moved the frogspawn further away.

As @Billdogg mentioned above, you can just let corals go at it and see who comes out on top for a more natural grown in look, or you can be more proactive to try to keep the warfare at bay. Eventually though a healthy tank is going to get overgrown and you'll have some battles and die offs. It's inevitable and a byproduct of success. There's actually a pretty cool thread on the forums here showing coral warfare between all types of corals and shows which ones typically win out in different scenarios. You can use that as a guide for placement or even coral selection. Some corals are much more aggressive/dangerous than others. Hydnophora comes to mind as a particularly nasty coral. Just search for "coral warfare" and you should find it. It's actually a pretty cool read as there are some gnarly pictures of corals destroying other corals. Hope this helps!

 

[Angelwolf21203]

I had the exact same questions, so thank you both for this thread.

 

[Miller535]

I had the exact same questions, so thank you both for this thread.

Me too!

I feel like I know where to place corals generally in my tank for flow amd lighting requirements, but not so much of what can sit next to what. Other then I try to keep leathers a little away from other corals, both because of their toxins, and just knowing they grow fast.