Fish Disappearance

[ISUAquatics]

Everybody, I'm perplexed. 20 gallon long, mixed reef. Lately, I've had two fish disappear. My royal gramma, that was alive and well one day, disappeared within 36 hours. Same thing happened to my blue neon goby. Now my firefish, that was great yesterday, looks disoriented. I ran water tests today, afraid that it was the parameters, and nothing popped up (pictures are below). I have a Tiger Pistol Shrimp and Watchman goby that are doing excellent, but I've noticed the shrimp wandering around every once in a while. Is there a possibility the shrimp could be a devil? The gramma regularly hid in the rock above the shrimps burrow, and the firefish would actually take up old burrows every once in a while. I've heard horror stories about the shrimp, so I'm suspicious.. I have pictures included below with the levels, and a picture of the tank. All corals are doing well, open, and growing exponentially even. I'm at a loss. The lighting for the chemistry tests is not the best. The readings were as follow:

PH 8.0
Nitrates 10-20 (I promise it's not 50, this is where the lighting doesn't help the background)
Nitrites 0
Ammonia 0

Tank is fed Coral Gumbo once a night (half a cube) and LRS Reef Frenzy Nano every other night. 

I have a 10 gallon nano I'm fully prepared to transfer the shrimp and goby to. They're fascinating to watch, but not at the stress of losing my fish in the main tank.

[NoOneLikesADryTang]

I'd say there's a decent change that your pistol got them... I am 90% certain a tiger pistol of mine, got a midas blenny. I didn't see it happen, but I did witness him being eaten by the pistol while the goby watched to make sure his meal wouldn't be interrupted.  

[ISUAquatics]

The firefish has died. I'm at a loss for words. I have a torch, hammer, Frogspawn, several Zoa's, and a bird's-nest. All flourishing. I now have two snails flipped over in the middle of the sand bed, dead. I really haven't ever experienced this before.

[NoOneLikesADryTang]

I'd probably move the pistol and goby, and see if it stops. 

 

Was your rock live rock, or was it dry rock? How long has your tank been up for? 

[Tired]

Pistol shrimp are scavengers, which means they get blamed for killing things. But tiger pistols don't normally kill fish. Maybe if the fish crammed itself into the pistol's burrow and didn't leave? But it's certainly not killing three fish in short succession. 

 

Salinity? Are you sure it's a tiger pistol? Any chance there's an electrical leak somewhere? What do you mean by "wandering around", for the shrimp? 

[Jakesaw]

22 hours ago, ISUAquatics said:

Everybody, I'm perplexed. 20 gallon long, mixed reef. Lately, I've had two fish disappear. My royal gramma, that was alive and well one day, disappeared within 36 hours.

I recently lost a Royal Gramma. Same thing, He was happy and out all the time, and then he just disappeared.  I could coax him out with food, but 2 days later I found the guy stuck to my Circulation pump.  

 

I think my Gramma was stressed because it all started when i added 5 coal frags.  It's a small 10 gallon aquarium and there was a frag on both sides of his lower cave and one right next to his Hiding hole in rock.

 

I only had him 3 weeks, but he was a happy fish but always very shy and could be easily startled even though he was getting along well with my Clown swimming together most days. 

 

Hope you find your fish and all area healthy.  But the Grammas can find hiding places pretty much anywhere you couldn't think of when they feel the need to.

[Tired]

Oh, there's two other things to consider: is it an AIO with filter compartments they could be in, and are there gaps in the lid? Check your filter compartments if they exist, and check for any gaps in the lid at all. Fish can fit through tiny holes. 

[ISUAquatics]

The electrical leak could be from a new Hydor Koralia timer I set up, although I believe it's unlikely as the Goby and Shrimp (as well as corals) are still thriving. There is a gap in the back of the tank that the canopy doesn't cover, so a jump could be a possibility. Salinity is sitting at 1.025. As for the shrimp, I've noticed from the time of the fish leaving the tank, the goby and shrimp have been wandering about more, as there's more space and less potential predators. I did think of something else. I recently added 5 coral frags, and all of my frags are glued. Could the glue affect the fish? It's reef safe Seachem Reef Glue.

[Tired]

The glue shouldn't do any harm, no. 

 

I would say the two missing fish are either hiding, or jumped. Now, the pistol may have indirectly killed them, by startling them into jumping with sudden loud noises at night, but so can plenty of other startling things. Best to cover that gap up- even if these didn't jump, something is very likely to eventually do so.

[ISUAquatics]

18 minutes ago, Tired said:

The glue shouldn't do any harm, no. 

 

I would say the two missing fish are either hiding, or jumped. Now, the pistol may have indirectly killed them, by startling them into jumping with sudden loud noises at night, but so can plenty of other startling things. Best to cover that gap up- even if these didn't jump, something is very likely to eventually do so.

Could the timer by chance scare the fish? I have the timer on 15 second increments, and although I really enjoy it, I could definitely see the vibration and "click" from the power heads switching back and forth causing a potential issue. 

[Tired]

Anything that happens suddenly could startle them, and something that's normally fine could startle them if they're on edge already from something else. The trouble isn't them getting properly scared of something (though that is, of course, also bad), it's them reflexively zipping away because they're startled, and shooting out of the water. 

 

I would imagine the timer wouldn't normally bother them, but it's possible it could one-time startle them. You also can't remove all sources of startling, because that would mean no snails or hermits (they can fall off things or click against the glass suddenly), no other mobile livestock, some sort of incredibly gradual start-up of the light, and no startling things outside the tank that the fish might be aware of. So, don't ever move suddenly or drop something near the tank. 

 

That's why you need a lid without gaps. You can't prevent the fish from being startled, so you just make sure they can't leap to their deaths if they happen to be in the wrong spot when they get spooked. If you already have a lid, and just have gaps, that's generally a pretty easy fix. Hell, you can use plastic wrap temporarily. 

[ISUAquatics]

I've tested the current and there seems to be no electrical leak. However, I noticed something yesterday. I recently set up a Koralia timer on my two power heads. On 30 second intervals, they don't agitate the surface nearly as much as before. With this, and the addition of several corals, is there a chance there was an oxygen depletion? I'm guessing that could be a reason the firefish appeared to be lethargic when I found it. The watchman goby and pistol are still doing swell. I do feel bad for blaming the shrimp, he's just been minding his own business.