Major Tank Crash- No Clue why

[live4spd]

I am utterly saddened by my recent tank events. About a week ago I had a couple signs from my clown trigger (5-6" long) He had sort of cloudy eyes and milky colored fins instead of clear. I thought ok, that's weird. So I did a fairly substantial water change just in case. 30 gallons tank is 130g.

Day or two after that my Blue Faced Angel is having same problems. (4-5") Also the trigger now has sort of a slimy coating. I take the water to my LFS to be tested. Nitrites were 0, Ammonia 0, PH=8.2, Nitrates 5ppm. Salinity was very low like 1.015 or so? I guess my hydrometer went amiss. So I start adding in salt over the next 3 days or so. I get back up to my 1.020sg that I normally keep. Fish are still looking bad, and now my 2 butterflies are in seriously bad shape. Same symptoms, died next day.

Getting desparate I changed another 30G and added Kent Expert RXP to the mix. sg holding at 1.020

Next day (yesterday) trigger is pretty much gasping for breath but still alive. Angel is also gasping for breath but still upright and moving close to normal. Cleaner wrasse which showed no effects of illness is found dead. So not knowing what else to do and knowing things are getting worse I call the fish store and ask them to house them for the short term.

Today I call the fish store and everybody is still alive, however, trigger and bluefaced angel are breathing on the ground. Not good.

Other fish are a spotted puffer (not effected) percula clown (effected but not looking bad) and a Bi color angel (who is only slightly effected) All are about 2"

My questions:

What happened? - I don't think low salinity caused this although I guess it's possible.

Why is my Puffer not effected?

Why are the smaller fish not effected as much as the larger ones? - More hardy?

Thanks for any help and please forgive the long ranting post. I am once again frustrated by this hobby and considering bailing out soon.

Please note this generally has been a reliable tank and never prone to sickness. The only possible change was I flirted with getting Xenia in the tank and bought one stalk. It was of course quickly devored and never seen again. That was one month ago.

Other Pertinent information possibly not included above:

130 Gallon tank
20g weekly water changes (pretty religous about this)
2 150G Rated Wet Dry filters
600GPH water turnover (1 quiet one)
Berlin Skimmer (1 quiet one)
800 Watts in heaters (I live in MI )
2x 96watt PC
50# live rock
60# LAVA Rock
120#+ of Sand
Feed- 3 cubes of frozen food daily
Sporiadically add Zoecon to the fishy food
Tank set up for about 2.5 years at this location

[FMarini]

Wow:
sorry for everything going amiss. So let me ask a few questions up front. What type of hydrometer are you using? Any idea what your buffering capacity is as well? Can you tell me more about the order in which the fish were introduced and how recently?
So first things first. Most like your clown was experiencing a small case of stress. It maybe that the trigger and angel went at it, or that you had some deteriation of your water quality. Triggers are hardy fish, so I'm going to say it was aggression related.

AS to what happened next....
It looks to me that one of your water parameters went awry from either the water exchange and or somthing you added recently to the tank. The cloudy fins and eyes are bacterial infections starting to roll in. Alternatively the cloudy eye could be a sign of a slight chemical burn in that your new water/water change maybe at fault. Any idea how close to your main tank water (in terms of Ph, salinity, buffer, etc) your water change water is? While 30gal in 130 isn't much, its it was widely off, or worse containing much undissolved reagents, this might have started the ball rolling. I say it was a water chemistry thing becuz your fish were succumbing sequentially. W/ the less hardy fish (or more high strung) contracting things first.
The gasping for breath description again tells me something went amiss w/ the water, and continued to be exacerbated by the water exchange. What is this Kent RXP stuff?

I too don't think it has much to do w/ the lowered salinity unless it was substantailly off what you and the LFS claim it was.
AS to why you little fish didn't catch anything is beyond me, are all your little fish the most established and longer term residents in your tank?

So as an immediate response i would increase water circulation and aeration in the tank, i would also add carbon (GAC) to the water flow just in case you introduced a stressor or poison. i would also start making lots of new water 9say 30-50% of the tank, and plan on doing a fair number of water exchanges in case something is currently in your water.
So as of today what is the situation w/ the angel and trigger?
These are just some ideas
frank

[live4spd]

Hydrometer- I have a cheesy glass drop in one that I normally use because I check the temp. with that as well. I do have a Coral Life Deep -6 that is rarely used. Occasionally I double check them. HOWEVER, I didn't read the instructions on seasoning the Deep 6 and it was consequently always off. (didn't know it until now) I have since seasoned it and it seems to be accurate now.

The Percula and Trigger were added when the tank was cycled about 2.5 years ago or so. The bi-color angel was added about 2 years ago with both butterflies at the same time. The Cleaner wrasse and the Blue face were added together about 18 months ago. The puffer is the newest at about 3mo ago.

Buffering- I haven't had a problem with PH ever so I have never added buffering capacity. that being said 120# of sand has always buffered the water for me. (I.e. if I check the ph now it'll be 8+ even though I've changed 60-70G in the last few days.) Myabe I'm wrong here...

On water changes the only thing I check is SG and Temp. It is not "seasoned" overnight I have always mixed water up and used it withen 3-4 hours. (enough to let the water settle and become clear)

I normally run GAC and change it 6 weeks. I was roughtly 3-4 into this "batch"

I checked with the fish store on the way home. Sadly the Blue Face Angel and my Clown Trigger died. My Bi-Color and Clown are also on their way out but still swimming around. Puffer was chewing on Formula 1 when I got. He seems fine. LFS seems to believe it was definately bacterial infection, whether or not it was the initial problems remains to be seen.

[daffynmark]

Just curious...what did your sand consist of? What type of sand is it? SD, Caribsea, ????

[live4spd]

Mostly Caribsea i think.