Tame the Lion
Well, lots of somewhat decent ideas on here. I have a rarer Pterois Radiata lionfish. Leo has been with me for 3+ years now and is very healthy with a good personality. You don't see Radiatas in the hobby as much because they are very poor shippers. He was only about 3" when I first got him and now he is about 5.5" and will be full grown at 9".
Baby Leo
If you want to treat a lion fish right and have a good relationship with them, then you need to be willing to invest the time that it takes train them to daytime feedings by hand. I don't know about Volitans, but it took me a good month or more to train Leo to get used to coming out during the day and take frozen food. It took much longer to train him to take food from my hand. When he was little, he often wouldn't take frozen food if it didn't look like it was moving. I started him on peppermint shrimp and damaged damsels (I buy wholesale) and slowly weaned him over to frozen krill and silversides. Even once he was trained to frozen food I would still buy live food for him sometimes because its fun to watch him hunt. I've almost never fed him freshwater fish as these have about as much nutrional value as mushrooms do for humans.
After awhile I was able to make a little bit of splashing sounds in the tank to get his attention to come and eat. The problem with hand feeding is that lions will often follow you around when you're working in the tank hoping for handouts. You just have to swish a little water in their direction so they get it and won't bother you for food. I feed my lion once a week about 3 silversides. Lions have a slower metabolism and don't need to be fed as often as other fish. They are like goldfish, they will eat as much as you give them and can get sick if you over feed them. It is very normal for them to follow you for food even when they're not really hungry. Get used to it and don't give in to over feeding.
My lion was very shy at first and would only come out at night, which is normal for them in the wild. So it is important to have plenty of ledges and caves for them to hide in. The smaller lions that don't like to swim a lot unlike Volitons, really love to perch on stuff and hang upside down inside caves. They are much more comfortable and happy when there are some places where they can "hide" and peek out at their world. My lion became more social and active during the day after a few months, but he still gets around at night.
Radiata lion fish and other smaller lion fish are crustacean eaters in the wild so they aren't that great at catching fish and I've definately had some "escaped" damsels in the past. So its best to get damaged/dieing fish that won't be too hard for them to catch. I'm not sure about Volitans, but as long as the fish in the tank with the lion fish are bigger than him or a lot faster to begin with the lion won't usually bother them when he grows larger. I even had a daredevil sailfin tang in with Leo a few years back that would swim in between Leo's fins and stay close to him and Leo never even tried to bite the fish. Currently, I have Leo in a 3x3' tank with a peppermint hog, a large bangai cardinal, 2 blue eye cardinals, a tomini tang, and a purple tang. He could care less about them. Its cool to watch him go around the tank investigating stuff, looking into nooks and crannies.
We do have a large skimmer on our tank, but we would have that regardless of whether we had the lion or not because we like to feed our other fish heavily. I don't really think he's that messy or dirty, probably my blue-jaw trigger is worse. I would tend to think most people that notice a real nutrient problem in their lion tanks are feeding too much or do not have adequate filtration.
My lion does like a lot of flow and often sits on top of my powerheads.
Now, on to the Volitans. These are the most commonly kept lion, because they are cheap and very showy. However most people do not keep them in adequately sized tanks especially for a fish that will grow up to 15" within a year or a little more. To put 2 volitans in a 90 gallon tank would be very unkind, much like making you live in your closet. These fish often grow too big for people to keep and then you have to find an lfs that will take it for you. These fish are much more than showy, "living artwork", they are pets and you should treat them just as well as you would your dog or cat.
Although the dwarf lions don't swim around as much they are still very interesting to watch and have cool personalites, they can also be kept with a larger variety of reef fish without harm. For a 90 gallon tank, I wouldn't put a fish larger than 5" max. Anything larger than that is just for personal pleasure and not really consideration for the animal you are keeping.
As far as catching lions goes, I have been able to herd mine into acrylic container/net just by directing them with my hand. I have never needed gloves because I have never needed to touch them, but you can do it for precaution.
When I first got my lion I was concerned about getting stung by him, but then I came to realize from observation/inaction that their spines are just there for their personal protection and they really won't go out of their way to sting you. If you are working in the tank with a lion you need to make sure that its not following you and also that you don't startle it. Lions startle very easily and this can make them become defensive which might get you stung if you are too close. If you need to work in close proximity with a lion it is important that you use slow, non-aggressive movements so they are comfortable and won't raise their spines. I can touch my lion on his tail and pectoral fins, he's used to it and never tried to sting me. Nowadays when I want him to move out of my way (because he's so curious when I'm working in the tank), I just touch his tail and get him to scoot away.
Lions are very rewarding to keep, but you shouldn't get one lightly because they aren't the easiest fish, they need plenty of areas to hide, and they live for a long time. Be sure this isn't a fish you will out grow in another year. Eels are a whole different lecture. There are easier to keep "aggressive" creatures with more personality and color than eels and groupers that aren't as likely to outgrow your tank.
More info: http://www.reefkeeping.com/issues/2002-11/fm/feature/index.php
Adult Leo