Why can’t I get Xenia to grow?
I have a small reef tank of around 100 l/22 gal and I can’t grow Xenia. despite others calling it a weed, I find it just disappears within a week or two of adding it. I’ve tried with three separate frags. I’m succeeding with polyps and LPS corals plus Clavularia, but Xenia just won’t grow. Would it be worth getting a larger specimen rather than frags? I’d like to grow this if possible as I love the way it moves. Kate Garner, email
dave replies: Some people have great success with Xenia (often too much!), while others have the same experience as you, but the factors responsible aren’t always that clear.
however, experience shows that Xenia tends to do best in less than pristine water, so if your nitrates and phosphates are very low (for example nitrates lower than 5ppm), this could be a factor.
Allelopathy (toxins from other corals) or direct aggression through stinging might also be to blame. Allelopathic chemicals can be dealt with to some extent through the use of activated carbon and water changes, and do make sure the Xenia is physically placed well away from other corals (especially lps).
Xenia prefer indirect current to brisk, direct flow, so position in areas of moderate water movement. they also like moderate lighting, so being in the upper to middle portion of the tank can help. they may also react poorly to lower ph, so try to maintain a stable ph of 8.2-8.3.
Finally, some folks claim iodine is important for healthy Xenia. You can add iodine in the form of lugol’s solution and this shouldn’t do any harm if done properly. it’s important to test before (and during) dosing to ensure you’re not adding too much; 0.06ppm is the level to aim for, which is similar to that of natural seawater.
i hope this helps. Do remember Xenia can look incredible but also be quite invasive, so you may wish to try and keep it contained on dedicated rocky ‘islands’. this can be a useful technique for managing its growth and keeping it in check.