2 fishes died within an week, help needed.

Docthrox · May 30, 2026

Ive been sent from the reddit thread, where I posted my story and concern:

https://www.reddit.com/r/ReefTank/s/CP3rnOghPt
With link to my reefbay account and all the information:
https://reefbay.com/tank/aliova
I'll couple paste my story and problem from the reddit forum, but I'm worried about the health of my fish. I had 2 fishes died on me while my parameters are all goed (high nitrate with a bit low mg+).
Nothing out of the ordinary, as in no sign of Ich or respiratory distress. I did noticed my royal gramma begin a bit more timid. However all of my fishes were eating well, including the royal and YWG.

Would love to have your thoughts on what the issue is? And how to prevent anymore deaths, or do I need to take steps?

Jay Hemdal · May 30, 2026

Docthrox said:
Ive been sent from the reddit thread, where I posted my story and concern:

https://www.reddit.com/r/ReefTank/s/CP3rnOghPt
With link to my reefbay account and all the information:
https://reefbay.com/tank/aliova
I'll couple paste my story and problem from the reddit forum, but I'm worried about the health of my fish. I had 2 fishes died on me while my parameters are all goed (high nitrate with a bit low mg+).
Nothing out of the ordinary, as in no sign of Ich or respiratory distress. I did noticed my royal gramma begin a bit more timid. However all of my fishes were eating well, including the royal and YWG.

Would love to have your thoughts on what the issue is? And how to prevent anymore deaths, or do I need to take steps?

Welcome to Reef2Reef!

I had some difficulty trying to evaluate the issue from the Reddit thread, it would be better to start fresh. Here is a post that explains that:

https://www.reef2reef.com/threads/s...sease-treatment-and-diagnosis-section.775547/

vetteguy53081 · May 30, 2026

Docthrox said:
Ive been sent from the reddit thread, where I posted my story and concern:

https://www.reddit.com/r/ReefTank/s/CP3rnOghPt
With link to my reefbay account and all the information:
https://reefbay.com/tank/aliova
I'll couple paste my story and problem from the reddit forum, but I'm worried about the health of my fish. I had 2 fishes died on me while my parameters are all goed (high nitrate with a bit low mg+).
Nothing out of the ordinary, as in no sign of Ich or respiratory distress. I did noticed my royal gramma begin a bit more timid. However all of my fishes were eating well, including the royal and YWG.

Would love to have your thoughts on what the issue is? And how to prevent anymore deaths, or do I need to take steps?

This I agree is hard to follow, Grammas are prone to flukes but will need much more info to make proper assessment. Is fish breathing normal or labored, loss of color, hiding more than normal as examples?
A video utilizing bright white light intensity with no blues best and at least 20 seconds in length

Beauha · May 30, 2026

difficult to tell. Fish are imported with parasites that do not appear until they are stressed and in a box they cannot escape. Maybe you bought lemons already done, maybe it’s a symptom of you other fish, being food shy, or countless other fungual or bacterial issues that grow when a fish is caught and shipped from an ocean to a box. It’s not easy on them

Docthrox · May 31, 2026

Just noticed my tailspot blenny also acting slow and not that lively, compared to yesterday. This a short movie.

He seems to be crossing the rainbow road too. I really dont know why it's happening. Any thoughts?

Docthrox · May 31, 2026

Well, he didnt survive.

Anything unusual with the corpse?

Paul B · May 31, 2026

How long is that tank running?

Docthrox · May 31, 2026

Paul B said:
How long is that tank running?

2 months, maybe a bit longer, 2.5months. 200l size.

Small spike of ammonia atm, so doing a water change as we speak.

The midas does seem a bit more stressed compared to yesterday. Could this be a respiratory distress? Due to gill parasites (fluke)? Or due to a small spike of ammonia?

The other fishes, kardinal. 2 firefishes does seem to be acting normally.

Mr. Mojo Rising · May 31, 2026

Its difficult to follow with the information split up like that, I don't have a password for reddit so can't see that. But it sounds like you had 7 fish in the tank at one point? In a 2 month old tank, it might have over loaded the biofilter, or else disease IMO. A full tank picture might also help give some clues.

Docthrox · May 31, 2026

Sorry about that, trying to keep everything at one place now.

Timeline as following

Started 2 months ago, started with dosing of bacteria.
At start up added fish food and bacteria to start the cycle.

19 april; when ammonia was 0 (after an ammonia spike) added 2 firefish, YWG, cleaner shrimp and pistol shrimp. They were a bit shy, but were doing great. Small spike of ammonia due to bioload, but went to 0 fearly quickly.

6 may, added 2 kardinal. The 2 kardinals were fighting for 10 days, so brought the larger one back to a LFS.

13 may, added 1 gramma. A bit shy, but was eating really well. And not fighting.

15 may: added midas blenny and tailspot. Both were doing good and eating well.

27 may: found gramma half eaten by hermit crab, day before he was hiding a bit more. He was at the LFS for a month. Did have a bite to eat, bit less than normal.
Torch died of Brown jelly disease.

29 may: Found YWG dead on the sand, also was lively a night before and ate mysis, was adding 6 corals. Acclimated and dipped.

31 may: this morning, tailspot blenny was almost non responsive, and died within 30min. And seeing the Midas acting frantically.

Preparing a waterchange of 20 liter, did them every 10days.

Dosing AFR, due to KH. And dosed Mg+ manually to correct the discrepency, till it's back normal again.

Mr. Mojo Rising · May 31, 2026

Personally I feel you are going too fast, I add 1-2 fishes then I wait a month, it takes time for the bacteria to increase along with the bioload.

I also see no hiding spots in your tank, many if the fishes you named instinctively want to find a tight cave to hide in. Without hiding spots the stress level is high.

The yellow watchman looks thin to me and I think I see a bite taken out of the tail. #fishmedics for more help. Good luck.

Jay Hemdal · May 31, 2026

Docthrox said:
Sorry about that, trying to keep everything at one place now.

Timeline as following

Started 2 months ago, started with dosing of bacteria.
At start up added fish food and bacteria to start the cycle.

19 april; when ammonia was 0 (after an ammonia spike) added 2 firefish, YWG, cleaner shrimp and pistol shrimp. They were a bit shy, but were doing great. Small spike of ammonia due to bioload, but went to 0 fearly quickly.

6 may, added 2 kardinal. The 2 kardinals were fighting for 10 days, so brought the larger one back to a LFS.

13 may, added 1 gramma. A bit shy, but was eating really well. And not fighting.

15 may: added midas blenny and tailspot. Both were doing good and eating well.

27 may: found gramma half eaten by hermit crab, day before he was hiding a bit more. He was at the LFS for a month. Did have a bite to eat, bit less than normal.
Torch died of Brown jelly disease.

29 may: Found YWG dead on the sand, also was lively a night before and ate mysis, was adding 6 corals. Acclimated and dipped.

31 may: this morning, tailspot blenny was almost non responsive, and died within 30min. And seeing the Midas acting frantically.

Preparing a waterchange of 20 liter, did them every 10days.

Dosing AFR, due to KH. And dosed Mg+ manually to correct the discrepency, till it's back normal again.

So - one key symptom is that aside from the torch coral, ALL the other invertebrates look ok. The soft corals are expanded and the shrimp looks good. Invertebrates are much more sensitive to water quality issues than fish are. That means 100%, you can rule out ANY water quality issues.

This is a fish disease. Trouble is, the video isn’t clear enough to say which one. It isn’t ich. If the fish are breathing really fast and not eating prior to death, it could be velvet/amyloodinium. F the fish eat ok but then die every few days, it’s probably flukes.

What fish are left? Can you get a clear video of them?

Docthrox · May 31, 2026

Mr. Mojo Rising said:
Personally I feel you are going too fast, I add 1-2 fishes then I wait a month, it takes time for the bacteria to increase along with the bioload.

I also see no hiding spots in your tank, many if the fishes you named instinctively want to find a tight cave to hide in. Without hiding spots the stress level is high.

The yellow watchman looks thin to me and I think I see a bite taken out of the tail. #fishmedics for more help. Good luck.

I thought maybe a fish or 2 per week should be fine. Was that to fast on my part?
Correct I was planning on adding extra rocks between the 2 towers down below for extra hiding place.

The hermit crab was taking a bite of the tail of the YWG when I saw him laying on the sand.

Jay Hemdal said:
So - one key symptom is that aside from the torch coral, ALL the other invertebrates look ok. The soft corals are expanded and the shrimp looks good. Invertebrates are much more sensitive to water quality issues than fish are. That means 100%, you can rule out ANY water quality issues.

This is a fish disease. Trouble is, the video isn’t clear enough to say which one. It isn’t ich. If the fish are breathing really fast and not eating prior to death, it could be velvet/amyloodinium. F the fish eat ok but then die every few days, it’s probably flukes.

What fish are left? Can you get a clear video of them?

A midas, a kardinal and 2 firefishes are left.
3 fishes died till now.
The cleaner shrimp and pistol shrimp are doing okay. And i dont seem to be missing some snails.

Anything different atm, is the way the midas is swimming, the others seem to be doing okay.

Just dit a 20l WC, the fishes are a bit spooked, I think.

I did see prazipro for fluke, however it seems its not possible to get a hold/buy it in europe.

Jay Hemdal · May 31, 2026

Docthrox said:
I thought maybe a fish or 2 per week should be fine. Was that to fast on my part?
Correct I was planning on adding extra rocks between the 2 towers down below for extra hiding place.

The hermit crab was taking a bite of the tail of the YWG when I saw him laying on the sand.

A midas, a kardinal and 2 firefishes are left.
3 fishes died till now.
The cleaner shrimp and pistol shrimp are doing okay. And i dont seem to be missing some snails.

Anything different atm, is the way the midas is swimming, the others seem to be doing okay.

Just dit a 20l WC, the fishes are a bit spooked, I think.

I did see prazipro for fluke, however it seems its not possible to get a hold/buy it in europe.

I saw the filefish flash/scratch. That sure looks like flukes! Many people in the EU are able to get Esha gdex or fluke solve. These both contain praziquantel.

Docthrox · May 31, 2026

Jay Hemdal said:
I saw the filefish flash/scratch. That sure looks like flukes! Many people in the EU are able to get Esha gdex or fluke solve. These both contain praziquantel.

I'll try to get a hold of it, is it possible to dose it straight in to the tank? Is it harmfull for corals or shrimps?

Jay Hemdal · May 31, 2026

Docthrox said:
I'll try to get a hold of it, is it possible to dose it straight in to the tank? Is it harmfull for corals or shrimps?

Prazi won’t harm invertebrates like coral or shrimp. Here is an article I wrote on dosing it:

https://www.reef2reef.com/threads/dosing-praziquantel-pzq.1105700/
I will say, when you have severe flukes, to the point where fish are dying, the remaining fish may not all survive the treatment.

Docthrox · May 31, 2026

Jay Hemdal said:
Prazi won’t harm invertebrates like coral or shrimp. Here is an article I wrote on dosing it:

https://www.reef2reef.com/threads/dosing-praziquantel-pzq.1105700/
I will say, when you have severe flukes, to the point where fish are dying, the remaining fish may not all survive the treatment.

Was reading up on Esha gdex, it does state that it harms corals and shrimps. I'll try to order some and start a treatment bucket.

Also horrible timing, leaving for a week this Teusday.

Jay Hemdal · May 31, 2026

Docthrox said:
Was reading up on Esha gdex, it does state that it harms corals and shrimps. I'll try to order some and start a treatment bucket.

Also horrible timing, leaving for a week this Teusday.

Unless they changed their formulation, it only contains praziquantel and that is reef safe. I don’t like to advise people to go against a manufacturer’s directions….

Docthrox · May 31, 2026

Understandable, trying to find a small aquarium to be able to quarantaine. I'll pick up the eSHa tomorrow at a LFS. I hope some of the fishes do survive.

Docthrox · Jun 1, 2026

Small update;

Found a tank second hand with everything needed to start a reeftank, a hobbiest stopped taking care of one. Just finished setting it up, added the eSHa gdx and the rest of the fishes. Not using a skimmer, I do use a spongefilter (without carbon), an airstone, heater and a wavemaker.

Midas was swimming the whole time at the top 1/3 of the tank, trying to breath at the surface and saw him hitting the sand couple of times. I hope this treats them all.

Worst part, I'm leaving for 4 days . Neighbor will add the remaining dose, on day 2 and 3. Already warned him, the tank is an Intensive Care tank. I do hope some of them survive.

My question;
Is it correct that i need to keep it isolated for atleast 21 days? Or longer?
Any other tips or something I forgot?

And ofcourse, many thanks for the help so far!