Leopard shark - Metal, Stray Voltage Concerns
One more question I neglected to ask, concerning metal and stray voltage in my tank. I removed my powerheads from my tank and I am now using bulkheads to feed current to the tank. This is coming from a Via Aqua 3600 powerhead in my sump (and I wanted to add at least one more).
<... stray current will/does easily pass (get conducted if you want) in seawater via continuous water contact...>
I've read however you should not even use powerheads in the sump.
<Correct!>
How can I provide adequate circulation otherwise. Are there any powerheads you can recommend that contain little or no metal that would disrupt my shark?
Thanks in advance
<... There are direct and coated magnetic drive mechanisms for external/emersed pumps... Bob Fenner> 

Coral Catshark
Hello, 
I hope this email finds you well. As always I have to thank you for the energy you expend helping us would be marine aquarists. Not that I expect you to remember but I emailed a few months ago regarding potential shark species for my tank. You advised me that coral Catshark (Atelomycterus marmoratus) or marble Catshark (Atelomycterus macleayi) would be best suited to my tank. Well after waiting for several months, keeping my tank minimally stocked, I finally got one. He is almost two feet. Only problem is I'm not certain if it is a coral or marble Catshark. Photos of the two closely related species aren't easy to come by and they seem to depict the same shark. Could you supply me with some distinguishing features between the two?
<Please take a look at www.fishbase.org or your copy of Scott Michaels' "Sharks & Rays".>
Also just to verify, I'll run my tank parameters by you to be certain everything is in order. 180 gallon (6' long, almost 3' wide), 50 gallon sump, trickle filter, 40 pounds of LR, sand bed, Aquamedic skimmer rated for 250 gal, two 802 powerheads. Is this enough aeration? 
<You neglected to mention your return pump and its rating. A test for dissolved oxygen would confirm either way.>
Temp: 79, pH: 8.3, Ammonia: 0, Nitrite: O
Fish: 4" black volitans, 2" fuzzy dwarf lion, 4" Naso tang, 3" tomato clown and couple of damsels. Tank has been running for 7 months. Compatibility?
<To me, if you are going to have a shark tank, have a shark tank. I would have left everyone else out. I do not see any out and out compatibility problems, but this tank seems overstocked or will be when everyone reaches full size.>
I've done my research and believe I've provided a good home for this creature. Nonetheless, your expert advise is of great value and duly appreciated. 
<Have a nice day! -Steven Pro>

Re: Coral Catshark
I had checked Scott Michael's book. He lists tank size for a coral cat shark at 75 gallons.
<That is the second time someone has said that. I am going to have to get a copy for myself. I cannot imagine he means as a final, healthy home. To me, a 180 is a good starter, but not the last tank you will need for an animal this size. They grow to three feet. The tank needs to be at least that wide, so they can turn around as adults, and three to four times that long, so they can swim a bit.>
<<Mmm, have checked... and this gallonage is only stated for small species of Catsharks. RMF>>
Given that figure, I assumed perhaps incorrectly that my 180 gallon tank would be able to sustain other fishes besides the shark. 
<Yes, an incorrect assumption IMO.>
Your point is well taken though that the fish in my tank, particularly the Naso and Volitans will eventually put too much strain on the system. However, so long as my tank parameters remain healthy, I am not certain why the tank needs to be species specific. If you don't mind, could you please elaborate on your reasons for a species specific tank. 
<Mainly because this is an incredibly large fish that is going to leave behind large waste and tax the system heavily. You do not need the additional waste from other fish. Plus, my recommendation generally separates the people that really, really want a shark from the casual shark hobbyist. If someone is not willing to have a species specific display, they are usually not going to save the tens of thousands of dollars to set up a tank large enough to house a shark permanently.>
I also have two more questions. The flow rate on my pump is 850 gph coupled with the two 802 powerheads and the trickle filter is this enough aeration and circulation?
<It seems like rather modest circulation to me. That 850 gph is a zero head pressure. I would ballpark it at no more than 500 gph actual plus the two 802's are rated at 400 gph (clean). Realistically, I would bet you have no more than 1200 gph total circulation.>
I'm trying to track down an oxygen test kit but haven't been able to find one.
<This should be fairly easy to find one on the internet.>
Also my lighting consists of 110 watt, 48" power compacts, is this too bright? 
<No>
Thanks for your expertise. I hope the questions of a novice don't put too much strain your patience. 
<That is who we primarily help everyday, new hobbyists. Have a nice day! -Steven Pro>

More shark questions 
Ran across your FAQs on the WetWebMedia site and am highly impressed and profoundly grateful. It¹s hard to get unbiased information regarding elasmobranchs (btw, if you¹re friends with the publisher of Aquarium Sharks & Rays, please smack those people for me and tell them to get busy!). 
<I am... indeed... and have... on repeated occasions... I was their/our industry rep... very slow to get works in print, the markets... painful for them/us, the industry, writers,  photographers... the "end-users".>
Couple of questions from reading your shark article.
You mention that vitamin supplementation is highly recommended. I feed my shark a basic diet of shrimp and squid and supplement with frozen cubes (shark cubes, Spirulina algae, herbivore, etc.) for variety and to get some green stuff¹ into his diet. He greedily eats whatever I provide, so can you recommend specific vitamin supplements to ensure he¹s getting the nutrition he needs?
<I would soak these foods with a liquid prep. like Selcon, Zoecon, Microvit, ahead of offering... if the animal/s are small (under three feet in length) and "sneak in" tablet types in their larger food items if they are more than 3 feet in length>
Regarding electromagnetic fields, I don¹t have any pumps in the water itself, but I do have several HEFTY pumps underneath the tank (enclosed in a wooden tank stand), which circulate water through canister filters and return water from the sump. For that matter, what about chillers, they have pretty big motors?
<Can be problematical depending on the vicinity of ferrous metals... but likely not a problem if you haven't experienced difficulties to date>
I also have oscillating water returns (www.sea-swirl.com)
that are electrically powered. The units themselves are mounted on top of the tank on the acrylic cross members, but the outlet tubes are in the water, just below water level. Should I fear any interference problems with my guy¹s ampullae of Lorenzini?
<Likely not much as stated above... the motors to the last are embedded in epoxy>
Lastly, in addition to moderating the shark¹s food intake (I feed to satiation once every 3 days), I regulate his metabolism by keeping the water cool (72-73 degrees) for a tropical shark. Is the concept of regulating metabolism by temperature valid, or is that just another Œfish story¹ I picked up in my readings somewhere? 
<This is valid, useful>
I will say that just by observation, he seemed to be hungrier on feeding days when my chiller was down for maintenance.
<Yes... in Biology, the Q-10 factor... doubling of metabolic rate with every increase of ten  degrees C...>>
Thanks again for your wonderful advice and commitment to the hobby.
J.D. Hill
<A pleasure and honor my friend. Bob Fenner>

265 Gallon Setup
Bob,
I hope all is well with you. Wanted to get your advice on what types of filters, skimmer, U.V sterilizer to purchase for a 265 gallon tank I will be setting up shortly.
<These are all posted on our site: www.WetWebMedia.com>
I know I'll need a wet dry.
<Hmm, no.>
I want to get one large enough to house the heater. Would a few whisper 5 hang on the back of the tank filters and some powerheads for water movement suffice? 
<No>
It will be a fish only tank with a bamboo shark, ward's Wobbie, and a few compatible fish. I figure I will want to get the best possible skimmer because I am looking to do the least amount of water changes as possible( the price of sea salt adds up). Also, are there any large angels or triggers that wouldn't bother the sharks if they were smaller than the sharks and placed in the tank last? Thanks for your help.
<Yes>
PS. I did inquire about the Ward's Wobbegong at the Marine Center and they will alert me when they get them in.
<All sounds good... now hit the WWM site... Bob Fenner>