Keeping Moorish Idols
hello Mr. Fenner,
<<JasonC here, Mr. Fenner is away diving>>
Is Moorish idol a coral eater? I have Acropora, brain and bubble coral and gobies in my tank. will they pick on them? thanks. 
<<From what I read, and I've never dared keep one, these fellows are strict vegetarians or at the very least sponges, tunicates, and macro algae - there is some limited reading on the site: http://www.wetwebmedia.com/idolfaqs.htm You may also want to post some questions on the WWM discussion forum to get some more opinions on this: http://talk.wetwebfotos.com/ 
Cheers, J -- >>

Moorish Idols- Dominance
Ignorance is probably bliss...After a year of looking I found a healthy eating MI at my LPS and added him to my reef tank (125 gal).  Last week I stumbled over two more healthy heating MI's and jumped at the chance to acquire them.  They are all three feeding but, when the lights are on the original MI dominates and pesters one of the new MI's to the point where it stays almost on the surface between two powerheads and on the brightest part of the tank (one side is lit by a 400 watt MH, the other by several MC's).
Sooner or later I would expect the one being pestered to succumb to the stress and contract something.
<You are likely correct here. There can be tremendous interspecific aggression in this species>
If I could remove the original MI for a period could this help?  If so for how long?
<Worth trying, but I do not give this a good chance of "success". I would remove the original fish permanently. A 125 gallon system is too small for three specimens. Bob Fenner>
Thank you
Roger  

Moorish Idol - Leave them be!  9/10/05
Hi Bob,
I have a 150 gal reef tank with Acroporas, Montiporas and several clams.
My fish include: 7 Anthias, 1 hippo tang,1 yellow tang,1 Sailfin tang , 1 tomato clown and a bubble anemone.
I am fascinated with a very beautiful Moorish Idol, eating like crazy at my local petstore .
Will it be ok with all these corals and fish. My real concern is about the clams .I will appreciate your opinion. Thank you.
Ramy, Canada.
>>>Greetings,
I would steer clear of this fish. While it may be "eating like crazy", whether it's eating enough of the right things is most likely a different story. A VAST majority of Moorish Idols do not survive more than a few days or weeks in captivity. Of the ones that do, and snare a hopeful buyer like yourself, another 95% percent of those are dead within a month or two.
It will in all Likelihood not bother your clams, but in all Likelihood it will not be alive in your tank in 6 months either.
This is one of those fish that should NOT be collected for the trade to begin with, and is best left in the ocean.
Cheers
Jim<<<

Moorish Idol/Blonde Naso (And Both in A 90g Tank…Not Good!), sys.  – 02/09/08
Hello there,
<<Hello, Tom>>
I have a few questions about my fish.
<<Okay>>
About two days ago I bought a Moorish Idol.
<<Mmm, one of my all-time favorites…I hope you have done your homework on this fish. Please do read through our FAQs on this fish here: http://www.wetwebmedia.com/idolfaqs.htm>>
I never really thought about getting one because I heard they don’t do well in aquariums,
<<Most do not>>
but this was an exception.
<<Let’s hope…>>
One of the guys at the store I go to pointed him out. He said that the fish was doing great (one of the best Moorish Idols they have seen) and he was eating well (just about anything you put in the tank), so I decided to purchase this beautiful fish (only about 3 inches).
<<Getting these fish to “eat” is not difficult in my experience...the problem comes from providing the proper dietary requirements. I have often heard where these fish fed well, yet still died “mysteriously.” On an up-note, there seems to be anecdotal proof that Zanclidae that will accept/feed upon New Life Spectrum pellets exhibit better health/longevity…providing they have been given proper environmental conditions (e.g. – not crammed in a too-small tank)>>
I put him in my 90 gal tank,
<<The Idol needs more volume than this, and preferably at least a 6ft tank>>
But I separated him from the other fish in the tank by a piece of plastic (with a lot of water flow) because I was worried my yellow tang would attack it (like it has for every fish I have put in. I figured if he saw the fish in the tank but couldn’t attack it he would get used to it being there.
<<This is called “habituation”…works sometimes…sometimes not>>
He is now eating very well and looks great. Is the success rate high for this fish now that he is eating well?
<<It is not… Getting these fish to eat is not atypical…getting them to thrive/survive the long-term, is. If you don’t have it now, I very much suggest you obtain the Spectrum pelleted food (small [1mm] pellets)>>
Now that I put the divider in the tank, I think it might have affected my blonde Naso (about 4 to 5 inches).
<<[sigh]… This tank is too small for the Moorish Idol… It is also too small for the Naso Tang… Placing “both” in this too-small system has compounded the issue exponentially>>
When I first put the divider my Naso ate out of my hand (like he usually does) and ate whatever I put in. Now a day later he doesn’t swim as much and he just swims by the food when I put it in the tank.
<<The fish is reacting to all the recent commotion and the now more restricting confines of this already too small environment>>
Could this be a result of decreasing his swimming room?
<<Indeed… And will only continue/worsen as health and behavioral issues, from “growing up” in this too-small tank…divider or not… (Have I said “too-small tank” enough yet?)>>
I turned off the lights and took the divider out, and left the lights off for the night. Will this strange behavior eventually go away now that the tank is back to normal?
<<Is hardly “back to normal” with the addition of this new large (potentially), aggressive, and far ranging/active fish. But yes, the Naso will likely settle back in…for a time>>
What can I do to assure my fish are always happy?
<<Well Tom, if I haven’t made it evident by now [grin], you need a “bigger” tank…at least twice the size of what you have now, for keeping both these fishes>>
Hope this wasn’t too long.
<<Not at all>>
Thanks for your time.
Sincerely,
Tom
<<Happy to help, Tom. Keeping Zanclus cornutus “is” a possibility (though let me be clear…I don't advocate these fish for the vast majority of hobbyists), but the odds are greatly stacked against you/this fish (and the Naso!) in this 90g tank. For any kind of hope for long-term success, I urge you to upsize these fishes environment. Eric Russell>>
<I do hope Eric won't mind my chiming in with a bit re Zanclus in captivity here... Have read in recent months diametrically opposed articles in two popular U.S. aquarium pulp press 'zines re this species... One alleging it was "still impossible", the other a little more optimistic, as Eric and I are here... Do read re our postings re on WWM. RMF>

Idol Reef Compatibility  12/22/08
Crew,
I have a friend who's Moorish Idol has been doing well for upwards of 2 years in her 180 gal fowler tank. Her Emperor Angel has attained full adult markings now and is becoming increasingly aggressive, particularly toward the Idol. She asked me if I wanted to take it to a more peaceful home. There is so little info on Idols compatibility on line. My 180 is a mixed reef with a variety of hard and soft corals, clams, and other inverts (Christmas worms, snails, shrimp, hermits, Aiptasia...). I don't know if it would be safe to put him into a mixed reef like mine.
Do they eat any corals? If so, which kinds would be least safe?
Thanks,
Joe
<Hello,
I would stay away from adding a Moorish idol to your reef aquarium. They will pick at corals and wreak havoc due to their size and somewhat destructive nature. These are best kept in extremely large reefs or at best in the ocean. If you like the look of the Moorish idol and want a more reef safe fish, then Heniochus diphreutes will do. Happy Holidays
IanB>