Dead angelfish - where did I go wrong?

[sdmariner]

I have a reasonably new saltwater tank running; it's been up for a total of about 6 weeks. 50 gallons, with live rock an a canister filter. I used a product with live bacteria to accelerate the cycling process - it claimed to be "instant," but I still waited 2 weeks before adding fish.
2 weeks ago, I added a flame angel and a blue tang. It took about 3 days for the angel to start eating, but after that it developed a healthy appetite and seemed to be doing fine.
2 nights ago, I added a seaclone protein skimmer to the tank - I ran it for one night, but removed it, since it was producing an enormous amount of bubbles in the tank and not building up any skimmate in the cup. When I first added it, the angel seemed to be fairly stressed; it wouldn't leave its cave.
When I got home from work (about 9 hours after I removed the skimmer and went back to just using the canister), my flame angel was lying on its side and gasping for air. It looked fine, except for a small white dot on one side. I tried giving it a 5 min freshwater dip (which seemed to perk it up a little; it tried to swim around the tank a little when I added it back in), but it died anyway within a few hours.
So - did I kill my angel with stress? Was it just an unlucky disease breakout? What should I do to treat a fish if something like that happens again?
My water parameters were correct - 0 ammonia, 0 nitrite, low levels of nitrate, with a consistent temperature of 78 F. The only thing which might be off is the pH (my test kit color scale is from brown to purple; when I test it, the color comes out blood red).

 

[beth]

What was the pH reading? Telling us the color doesn't help as different kits show different color.
Also, you should use the skimmer. It likely needs adjusting. Read the directions to the skimmer through and through and follow them exactly. Including rinsing the skimmer out before use.
Also, what are your nitrate readings?
Also, a 50 gal tank is not appropriate size for any type of tang. Is it possible that there was aggression between the tang and the flame angel?

 

[btldreef]

1) flame angels, as with all angels, need established tanks
2) tangs do not belong in a 50G
3) bottled products claiming to jump start the cycling process are usually garbage
4) sounds like there might not be enough oxygen in the tank. Can you post a picture of your tank and let us know what model canister filter you're running?
5) how is the tang acting?

 

[sdmariner]

I was hesitant about the water cycling product - however, I monitored the ammonia and nitrite levels carefully, and after an initial spike, they've both stayed at 0.
I just checked the pH again in the daylight - it's right at 8.1, with a nitrate reading of 10ppm.
I'm using a penn-plax cascade canister. There isn't an airstone in the tank right now - however, I have the filter output set up to agitate the surface. I wouldn't expect it to be an aeration issue, since problems only developed after I flooded the tank with bubbles for a night.
My tang has been acting fairly shy - it has a particular cave it hides in frequently. I haven't seen any aggression between any of the fish in the tank. The tang is only about 1.5" long at the moment.

 

[beth]

It looks to me like your set up is more for a fresh water tank rather than marine. For instance, the blue pebble substrate you are using, the broken urn decoration. What is that pottery made of?
I would say your system is just not set up for what you are trying to do. Do you have reference books on marine aquaria and how to setup and maintain a saltwater aquarium?
You can keep a few small fish in a 50 hex, but certainly not tangs, nor most angels. In my view, you need to start the process over with some research under you belt on your part, and help from your fellow hobbyists here.

 

[flower]

Hi and welcome to the site.
Beth is right, you need sand, I don't even like crushed coral. I really think the biggest mistake on your setup is that there are no power heads to circulate the water. You would never use an airstone in a SW tank....a couple of air lines without a stone would help a little until you can get a power head. The wave is the life of the ocean and your saltwater tank. Oxygen is less in saltwater because it's heavier, without the power heads your fish can hardly breath. Tangs are very active fish, and if it's hiding acting shy, it's stressed big time.
There are no short cuts for cycling, I used the "starter" stuff when I added 4 seahorses at once to try and keep down any possiblity of an ammonia spike, I normally only add one fish at a time, with weeks in between, so I was nervous...but certainly not use it to cycle the tank. The small amount of live rock you have may have saved the day for the tang in regards to cycling. The ornament is okay...I was thinking of using that very one in my tank, it is made for marine or freshwater tanks, and it will seed just like live rock.
My advice is to return the tang and redo the tank...get a power head and live sand, also some more rock. I'm sorry about the angel, they are so sensitive and need very stable water conditions and there is just no way a brand new tank can have that consitently.

 

[sdmariner]

Alright, thanks all for the assistance. I had decided to go w/ gravel over sand after reading in my reference book that:
- either would work for a marine fish-only aquarium
- sand needs to be stirred to prevent toxic buildup
And a general hope that gravel would be easier to clean than sand.
I definitely remember reading that the minimum tank size for a tang was 30 gallons, but I suppose I'll have to figure something better out.

 

[beth]

I don't know what reference book you are using, but it seems to have a lot of bad information.
I would suggest getting "The Contentious Marine Aquarist" by Bob Fenner. An excellent reference book for beginners with a wealth of information and help.

 

[sdmariner]

ok - thanks! I just ordered it, should be good to have more info