Blue Hippo Tang behaving strangely
 

Hi everyone!

I am new to the forum, although I've been creeping it for a few weeks now whenever questions arise. I have a 150g saltwater tank that's been up and running for about 3-4 months now.

Two days ago, I added a blue hippo tang to my tank. I had been eyeing one for a while, but wanted to wait until I felt that my tank was stable enough (now I'm afraid I added one too soon!). The first day went smoothly and the blue tang swam around happily, ate some seaweed from my clip, behaved pretty much normally. Last night he started acting a bit weird. He began breathing heavily, laying on his side, etc. Today, he's no longer just laying still, but instead swimming in crazy loops and circles around my tank, before laying down for a second, and then resuming his weird dance. He is still breathing somewhat rapidly from what I can tell.

I'm really worried that something is wrong with him and I would like to diagnose and treat it asap if possible. I've browsed past forum posts related to this issue but I can't find any information that helps so far.

Some stats about my tank (if it helps at all) --

Current fish:

1 maroon clownfish
3 black & white ocellaris clownfish
2 ocellaris clownfish
2 snowflake clownfish
1 yellow tang (about 3 inches)
1 blue hippo tang (about 2.5 inches)
3 hermit crabs

(side note: I realize I have a ridiculous amount of clownfish in there. Surprisingly, they all get along really well. I have yet to see a single spat or any sign of aggression from one to another, even at night. I don't plan on adding anymore though)

Tank parameters:

Temperature -- 78 degrees
Nitrate -- 10ppm *
Nitrite -- 0ppm
pH -- 8.0
KH (carbonate hardness) -- 140ppm
Alkalinity -- 200ppm *
Calcium -- 800ppm *
Salinity -- 1.024

*** anything with a star next to it is something I'm concerned about, especially my ridiculously high calcium levels!

I just performed a 20% water change, and I'm hoping that will lower the calcium level. I'll probably perform a second water change in 48 hours, because I realize it will take a lot of effort to lower the amount of calcium in the tank. My alkalinity and nitrate levels are also a little high, so again I hope the water changes help.

If anyone has any advice on what to do in order to make sure my hippo tang is ok please let me know! If you need any further parameters I can provide those as well.

Also: I do have a protein skimmer in there. I set it up about 5 days ago and it's almost fully broken in. I'm not sure if that has any effect on what's been going on. (also also: sorry for the ridiculously long post!)

Yes, your calcium is very high but it sounds like the little guy is just a bit stressed and trying to get used to his new home! These tangs are shy! It's normal behavior for this type of tang to lay on its side and hide beside rocks for periods when it feels nervous about something and get back up when it feels the that the scare instigator has gone away. Or so I am told (I have a tang, a Scopas tang - NOT a Hippo though).
I would dim he lights for about 2-4 days to keep him calm - and attach some algae to a clip to keep him occupied. Before blitzing your tank with any medication, I would watch him AND all your other fish closely for the next several days. Look for any of the signs below:
He's still eating, right?? Are there any spots on him or on any other of your fish? Any shredded fins or red marks?? Are his eyes cloudy?
Nitrates are generally NOT a problem for fish unless they rise above 50 or 60 PPM, but if I were you I would looking into getting a biopellet reactor or start dosing the tank with tiny amounts of vodka (but do your research BEFOREHAND - you can find dosing charts online) to bring your nitrates down.
200 mg/L (ppm) Alkalinity is approximately equal to 11.5 dkh. A bit high but not bad. Yes, I agree - a couple of water changes with RO water should bring the calcium level down. High calcium levels shouldn't harm your fish in the short term but with the levels you have you'll have to do a LOT more tank and sump maintenance because your pumps, powerbeads and plumbing can get clogged quickly!

Hippo tangs can be idiosyncratic, certainly, but heavy breathing and swimming in rapid loops and circles is not a good sign. Not sure there's much to be done other than just reducing outside stresses.