what is wrong with my frogspawn?

[attempt]

last week i purchased a diamond goby, which i have since caught and removed from the tank and taken back. besides burying my blue tipped tongue coral, and making mountains in my tank, he stirred up enough sand and debris that my tank was a cloudy mess.my frogspawn is looking none to healthy. It withered away to almost nothing at first, it has since started getting a little larger and looking a little more normal. tonight it seems to have a "bubble" on it... is this bad? do i need to be concerned?
ammonia -0
nitrite - 0
nitrate - 20ppm (jumped up after the introduction of the diamond goby)
alk 4.5
ph 8.2
salinity - 1.0245
calcium 450
I know the first thing that will be said is oh well its due to your nitrates
I added that coral when my nitrates were 30ppm several months ago.
There has never been a problem with it swelling up in "full bloom"
So before im attacked for that i would like to hear some other possible causes.
I did dip the frogspawn and the tongue corals last sunday also did a 12 gal water change (have a 29 gallon tank)

 

[attempt]

sorry for the size an quality of the pic :\

 

[Anonymous]

hi there,
do you think you could have accidentaly hit your powerhead so it blows to much water over the frog spawn? i have seen that happen in my tank. they are really tempermental towards flow.

steven

 

[crazygirl]

I notice that your salinity is a bit low you might want to try to bring it up. I have noticed mine kind of shrives a bit when it start to get a bit low .. Bring it back up a little at a time . .Also make sure that it is getting full light. also have noticed mine when it is shadded by something that it doesn't look so well.

Good luck and keep us posted.

crazygirl (heather)

 

[aliendomain]

That big bubble looks like a gas pocket. I've never heard of that happening to a coral though. If you have "The Reef Aquarium: Volume One" you may want to look at the diseases chapter.