Can I save this DYING NANO?

Lord Mort

Premium Member
Hi All,

I've been out of the hobby for at least 15 years. Long story short, I inherited a 10gal nano reef that was neglected for at lest 5 weeks. Due to the nature of my friend's sudden passing, I have NO prior info on this tank's parameters other than temp and salinity. 78° 1.024

Here's what we got... maybe 10 lbs of LR. Some Zooanthids, another soft coral that I can't ID, 2 large snails (little bigger than a golf ball) a couple just like them but smaller, 2 fish (now dead) and an abundance of bristleworms and algae.

I drained the tank 1/2 way and moved it as carefully as I could. inevitably, a lot of stuff was stirred up so I did a complete water change (25% at a time, 4 more times after refilling) The water I used was purchased from a big box store and is actually Pacific Ocean water. (not a synthetic mixture)

I had assumed it would be perfect for an aquarium but after losing both fish in 2 days I decided to take a closer look. Sure enough, the salinity of the ocean water is 1.026. Is that enough of a change to kill fish?

The water smelled bad so I took a sample back to the big box store, they did a test (including a second one for ammonia) and everything came back clear, no ammonia, no nitrates/trites and pH and Alk is "in range".

I did another 50% water change and added a second power filter with an "ammonia" cartridge just to be sure.

Another odd thing is this abundance of bristleworms. iirc, you don't normally see them... but these are everywhere. They're moving but they seem sluggish.

I know I need to get a cleaning crew but everything was closed today.

I would appreciate some feedback/advice. This belonged to a good friend of mine and I would hate tor these corals to be lost.. if there's any chance of saving them, I have to try.

Here are some pics... is it too late for these zooanthids? They still "fluoresce" under the blue light.


New member
1.026 is fine. What is not fine is what ever the salinity was in the tank. If the salinity was say 1.024 and you raise it quickly to 1.026 it can adversely affect the fish.. anyway, not saying that is the problem.

Keep in mind some corals dying in a tank releases toxins which kills fish and inverts as well. I would just wait it out. take out whatever dies as quickly as possible, any bad looking zoas, remove and place in a second qt tank to see what you can save, but don't keep dying stuff in the same tank as the good stuff. That big zoa piece seems pretty ok, so I would definitely try and save it.

lastly, when you do water changes, make sure to get the temp the same as the tank's temp before putting it in the tank.

Lord Mort

Premium Member
idk if this matters but the bed is crushed coral. I gave it a light vacuuming as I was afraid to disrupt the biobed underneath. Would you still recommend a more thorough cleaning?

Also, I've been out of the game so long... what critters in particular should I look for to add to the clean up crew?



New member
Yes, give it a good vacuum, that bed looks like there is a lot of decay in it. as long as you vacuum out the bad stuff into a bucket and dump it and not recycle it into the tank. for now I would keep checking for ammonia before adding COC. If there are no traces of ammonia and nitrites then I would just add 2 blue leg hermits and maybe 2 nassarius snails. You say there are bristle worms, but I would consider removing some if they are too many. The bio-load is out of balance and I would rather say you should try and stabilize the tank now. I would also look out of any hidden dead snails, anemones and corals and remove them asap (if any)


New member
oh and let me clarify the sandbed vacuum. Don't throw over the bed entirely, the top part of the sandbed should be vacuumed. So the lighter part of the sand. Don't disrupt the bottom part as that will be where the anaerobic bacteria culture lives.


Cloning Around
Staff member
RC Mod
Premium Member
A 10 gallon tank that has been neglected for 5 weeks. Does that neglect include refilling with fresh water to make up for evaporation? If so, the salinity in that tank could have been much, much higher, but occurred over an extended period, so the critters adapted. A rapid change to a much lower SG (even if it was 1.026) could have resulted in the fish death.

You also mention the water "smells bad." If that smell is the "rotten egg" smell of hydrogen sulfide, that could be what killed your fish (and isn't something any hobby test kit will test for). Hydrogen Sulfide is produced in the anaerobic areas of the tank, often in deeper sand or crushed coral beds. Moving the tank could easily have released a significant amount of Hydrogen Sulfide.

More about Hydrogen Sulfide in our tanks.


Lord Mort

Premium Member
Thank you guys.
[MENTION=354375]Reefer902[/MENTION] Thank you for clarifying, I did go about half way in to the sand bed. I had an inkling that it would be bad to go all the way down.
[MENTION=1075]Anemone[/MENTION] The smell was between rotten eggs and "bad fish" but it makes total sense that the hydrogen sulfide was released. It just couldn't be avoided.

In hind sight, I should have separated the live stuff and taken all the water out of the tank. It just happened so suddenly I didn't have time to prepare.

So far, I had to throw out most of the "brown polyps" (I dont know what they're called) But there are a few left on the back of a rock that look pretty good and should be able to repopulate in time.
The Zoas are doing somewhat better but I fear that a small portion has died. I'm concerned that it may spread but I don't want to pull the whole rock. Is there a "critter" that would clean that up?