I am not disagreeing with any prior posts on whether to keep a shark or a ray or both in a home tank. I have a 6 mos. old bamboo shark which is around 14". Sharks are messy therefore I have 2 overflows which run around 270 gph
each (I think it's each). I have a powerhead in tank and a mag 18 for my return which keeps everything moving. I placed two outlets on the return...one mid tank level pointing in one direction and one at the bottom pointing in another direction. When considering a shark....full grown size is key. They can live for a very long time.....and one way to keep their size down is to moderate how much/often you feed them. I am not saying starve them...most sharks when well adapted will eat until they are full. These sharks (as most are) are not reef safe for 2 major reasons....they will nip at your corals and the like, and they need a lot of swimming room especially when they get bigger. The key to purchasing one is to have your LFS
get one for you (without paying)...put it on hold first. The next step is to let them keep it for a month. Check on it every couple of days (if possible) and ask them to feed it while you are there if they haven't. This way you can tell whether it's a hardy shark who will adapt well or one who may not. I cannot suggest smaller than a 180gal tank for any home shark. In fact the bamboo is probably one of the one home sharks you can keep....possibly and epaulette but I wouldn't push it.
As far as rays go....you need at least a 240 gal
tank that is deep since rays are very wide....they are also not reef safe and may not do well with a shark. Most home sharks hang out on the bottom of the tank...so do the rays....which will cover themselves in the sand. You don't want the shark skmming the bottom for food only to have it hit the ray and start something you can't stop.
I am fortunate in that my shark has always eaten well (I did the steps above of watching him) and mine doesn't lay on the bottom all day. He is freqeuntly found swimming around the nooks and crannies of my artificial reef.
Compatability (sp?) for them is tough. See below for my stock...minus my trigger. Other than my koran angel which won't be added for years I don't have any other plans for more stock other than maybe a tang down the road.
The one positive that I have found with my shark is his hardiness.....which is why I would tell the original poster to not get the blue dot ray....they are VERY hard to keep out of their natural environment. My shark was introduced after I thought my cycle was complete.....it wasn't and he has survived as if nothing was wrong at all through the last couple of weeks....I obviously suggest you wait until you know your cycle is complete before acclimating anything.
and this is a forum so all opinions and thoughts are welcome...that's why we are here