What could be killing all my fish

i think that eel has a secret lair in the substrate and that's where all the bodies are.


besides that, that's a really heavily stocked 29 gallon and that livestock was added really fast. that might signal fish death, but not missing bodies... unless that's coupled w/the CuC... but still... seems odd.

is the orange star a linkia?

I am partially wondering if the star (or a star) is the culprit...

doubting it, but wondering...

 

Well I'm convinced: definitely aliens.

 

I know you said your water tested fine but did you have it all doublechecked by another person with another test kit? Maybe the test kits aren't working properly or are past expiration and are giving false readings?
Also what is your water source, are you using RO/DI water or tap water? It's possible there is something toxic to the fish and marine organisms over time in the water if you aren't using RO/DI. Actually it's possible something could get through an RO/DI unit as well but less likely.

I would recommend if you are going to restart, stock more slowly and more moderately. Start from scratch with dry rock and new sand and stock slowly and carefully ensuring you're not introducing any pests or diseases.

In retrospect I'm not sure there's any way to determine the cause especially without a lot more detail, if it were me I would just restart and be extra careful about every little detail from water source, rock/sand source and type to livestock choices.

Good luck!

 

i definitely agree with screwtape i am not sure how likely it would be for you to have had introduced a fish killing pest twice in such a large time span and by starting from scratch if your water sources and rock/sand sources weren't identical or similar from before when it happened. Also, are these identical or similar livestock choices from the initial disappearing instance?

 

And just as important, i think this was stated before but, definitely need to slow down the introduction of new fish making it about 4 to 6 weeks in between to allow the system or beneficial bacteria to adjust.

 

Yes I also had the water tested by the local fish store. they could not figure it out either. we only use RO water in the tank. when we started from scratch this time we completely emptied the tank. made sure we rinsed everything good, put all new sand and new rock in (that was even bought at a different store that the first stuff had been bought in). we again set the tank up - let it cycle for 3 months making sure it went through the entire process then added the cleaner crew and let them be before adding fish. put the fish in and a month later they started dissapearing. now the first time it took a year for this to happen (until all the fish were gone) - we also had some problems last time with adding the fish too far apart because the ones that were in there, although not agressive fish, would become territorial towards the new fish.

 

no they are different livestock this time. the only livestock that was the same is we had a clown fish and turbo snails in both tanks (not the exact same ones from first tank though - new ones).

 

you sure the eel isn't buried in the sand?

Could the fish be jumping out of the tank and gobbled up by another pet?

 

Have you tested the tank for stray voltage?

Could also be a crab or eunicid worm.

 

Maybe the fish in the second batch were all collected poorly, cyanide or something. Maybe try getting your livestock from another source next time?

Or maybe adding them all at once did produce some sort of a slow ammonia/nitrate buildup that had cycled through before you were able to test it? Or perhaps there was a spike when you added them and that did some sort of damage to them. Regardless, it's probably safer in the future to stock more slowly is the point I'm trying to make.
If they're added in the correct order and are not aggressive you shouldn't have any major aggression issues, don't let one bad experience scare you off of stocking more slowly. Maybe post your stock list ahead of time and get other opinions on stocking order and whether anyone else has had aggression/territoriality issues.

Are you using RO only or RO and DI? That could potentially be a source of contamination if you're not using a DI stage. The fact that the first batch died and then within a few months your next tank's livestock died might lead you to think that something in your home is the culprit whether that's water or maybe some sort of cleaner or air freshener or something you started using in the room?

Just throwing out some ideas...