New fish die, coral & inverts doing fine?

[Fryman]

I’m having problems keeping new fish alive in my tank

My tank has been set up for about 6 months. It’s a 55 gal w/ 15 gal sump.

Parameters:
pH: 8.2 (morning)-8.4 (evening)
temp: 80 degF (+/-1)
Ammonia, Nitrite, Nitrate: 0 (not detectable)
Phosphate: 0.5ppm Ca: 480

I know the phosphate is a problem for coral growth, but everything I read states fish should be fine at well over 0.5ppm PO4. My coral seems to be doing well: I have xenia (4 stalks), torch coral (2 heads), ricordea (2), zoas (~20), clove polyps (50+), elegance coral, frogspawn & leather. The softies are growing alot, the others probably have their growth stunted right now so I’m working on the PO4 problem (got a reactor). My inverts are very active and appear perfectly healthy.

But in the past couple of months EVERY new fish I’ve added has died. First, a pair of clarkii clowns I added about 2 months ago died in less than a month. Then I lost a coral beauty within days of adding him. This last week-end I lost a pair of oc. clowns in less than 24 hours. I still have two damsels and a firefish that have been in the tank pretty much since it was cycled that seem healthy. Well, the firefish is a nervous little dude, but I figure that’s just how he is.

I always follow the recommended acclimation procedure: float the bag & add a cup of tank water every 10-15 mins until full, then empty half the bag (outside the tank) and do it again.

The pair of clowns from last week-end acted a bit odd when I added them. They seemed agitated, constantly swimming around the tank like they were trying to escape. They disappeared overnight. I’ve looked everywhere for them but was unable to find either corpse. I’m sure the crabs have eaten them by now. I have a couple of emerald crabs, 2 fire shrimp, maybe 7 large nassarius snails and at least 15 hermits (mostly blue-leg) that are all very greedy little eaters so left-overs don’t last long in my tank.




I’m looking for suggestions on root cause(s) and solutions. My (admittedly weak) theories so far:

1) Too many particulates in the water? I have pretty much no mechanical filtration in the tank right now (no easy way to do the way my sump is setup) and I’ve noticed very small particulates floating in the water. It doesn’t look too bad to me but I’m worried enough about it that I’m trying to figure out a way to rig up a couple of filter socks.

2) Stray voltage causing stress? I measured 8VAC w/ reference to the GFCI ground which dropped down to <0.5 VAC when I unplugged a light above the sump. I removed the light, but have serious doubts about this as a cause.

3) High carbon dioxide/low oxygen levels? I don’t know what would cause this or even how to test for it, but it seems like something that could kill fish while leaving the coral & inverts mostly unaffected. Also the fish usually seem to die overnight, when I would expect O2 levels to go down and CO2 to go up. The fish I still have completely disappear into the live rock at night.

Other ideas? What else should I check? I thought fish were supposed to be easier to keep than coral, but my experience has been just the opposite.

[Scott B]

Have all your fish "disappeared", or have you found them dead? Maybe they are jumping out of tank, into sump etc...

[Fryman]

Originally Posted by Scott B

Have all your fish "disappeared", or have you found them dead? Maybe they are jumping out of tank, into sump etc...

I found bodies for the first 2 clowns and the angel. The pair of clowns this week-end has me a little perplexed, you'd think they were too big to just "disappear" overnight....but I figured they were dragged into the live rock by crabs. My live rock has a lot of hiding places. I found the coral beauty in the rocks, jammed into a space I'd have never figured he'd fit, with the big emerald crab and several hermits chowing down on the body.. yuck.

The tank has a cover, and there is very little space between the overflow and cover. They would have to jump over the overflow wall, but not too high or they'd hit the cover. There may be enough room to squeeze between the top of the overflow and the tank cover, but it'd have to be one incredible jump! I suppose it's possible and so I'll check the sump when I get home, but I seriously doubt they are in there.

Would be awesome to find them alive and well in the sump tonight, though...

[Lynnmw1208]

you sure someone isn't eating the fish? have you ever found a single body of these dead fish? I know it's hard with nassarius snails around, but perhaps one of your crabs went rogue. I just don't trust em.

[Dingo44]

Is your cover a glass cover? If it is, sometimes that can inhibit gas exchange and your O2 levels could be low.

[Fryman]

The cover is acrylic.

The biggest crab is big for an emerald, but I don't think he could take on a clownfish, and no way he'd take on a coral beauty. Not alive anyway. I've never seen him take any interest in live fish either.

[HanoverFist]

acrylic/glass same diff. Need to open up tank and let it breathe.

[MammothReefer]

whats your salinty

[Fryman]

Originally Posted by MammothReefer

whats your salinty

1.024 measured w/ refractometer

[MammothReefer]

Originally Posted by Fryman

1.024 measured w/ refractometer

whens the last time you calibrated it?

[Fryman]

Originally Posted by MammothReefer

whens the last time you calibrated it?

When I bought it, at least a few months ago.

I will check it again tonight.

[stingythingy45]

What's your alk?
Do you have a skimmer?
Do you supplement or dose anything?

[duncantse]

It's weird how you have a firefish and a damsel and corals in the tank that is still thriving. What kind of damsel do you have? It might be bullying the new fish.

[Fryman]

Yeah, I'm an idiot.

They were in the sump. I guess that jump isn't as hard as I thought...

Good news is they are just fine. Bad news is the damsel IS a big bully, and I can't catch him.

[Fryman]

I'm soooo psyched the clowns are ok. Stupid of me not to check the sump. I'm very relieved, THANKS SO MUCH for the advice!

Now I'm worried about the big damsel. I actually caught and moved the little damsel into the sump a couple of months ago. He was really beat up by the big one (and thus easy to catch). He's been living there by himself for awhile until the last few days when he got company. I thought the clowns were big enough the damsel wouldn't bug them, but I was wrong.

I've tried in the past to catch the big damsel but he's eluded me many times. I tried the soda bottle trap, vase trap, and even took out like half the water and live rock (back before I had all this coral). That little **** is a crafty one.

[ddrag2]

keep an eye on your oxygen levels anyways. if for some reason your skimmer turns off, there is little dissolved oxygen left in the water depending on how well your powerheads stir. I have seen someone with a mystery problem like yours spend over $500 replacing fish and equipment until he just realized his sand bed was too thick and was depleting the O2 in the tank at night when photosynthesis stopped. You can buy a cheap test kit for this. Oh yeah the fish always acted weird and tended to jump into odd places. In fact a lawnmower blenny actually jumped from the tank into a full 5 gallon bucket a few feet away. Only problem was it was fresh water but it proves how observant some fish are.

[hollister]

You need good water flow and no lid for gas exchange.
Where they breathing hard.
Your salt water tank recived oxygen through a gas exchange created by good water movement.

[duncantse]

Originally Posted by Fryman

Yeah, I'm an idiot.

They were in the sump. I guess that jump isn't as hard as I thought...

Good news is they are just fine. Bad news is the damsel IS a big bully, and I can't catch him.

Im glad that your clowns are okay. Another way to catch your damsel is to dig a hole in the sand and then drain almost all your tank water.

[Fryman]

I don't see them breathing hard. But I hear you about O2, so I hooked up an air stone I had around from a freshwater tank. I will check out the LFS for a test kit tomorrow.

I DON'T have a skimmer. I didn't think I needed one, since I have no measurable nitrates. I DO however have some chaeto in the sump on an opposite light cycle from the main display. Also, although the main tank is covered, the sump is not. I'm lucky the clowns didn't jump out of the sump, actually.

I didn't have the chaeto before (when the other fish died). So it's possible I'm getting low O2 sometimes.

[stingythingy45]

A skimmer does more than just remove organics that result in nitrates.
It also aerates the tank and helps keep PH up.

[Chris27]

Without adopting a proper QT regimen you may very well continue to experience losses. There are a host of factors that could contribute to their demise....here are some examples.

1. Rapid change in salinity - LFS tend to keep some tanks at a lower salinity, acclimating for an hour may not be long enough for some of the more delicate fish.... especially ones that were in the ocean last month.

2. Parasites - Crypt is a slow killer, but Brook is not, and again most fish coming from a LFS have been in a parasite infected tank at some point between the time they left the ocean and showed up in the store.

3. Stress - The trip from the ocean or from the supplier in LA is hard on the fish, a day or two in a bag of water without food or O2 is hard on them. Seeing a fish alive and well, and eating, at the LFS for a week or two is a good sign the hard times are over.

The above items can easily be dealt with in a QT/Hospital tank, having a small tank where you can adjust things rather quickly can be the deciding factor between a happy fish and a dead fish.