Fish keep dying, getting ready to call it quits

[Mchava]

Looking at your picture and how you tank looks like, I’d question your “professional” tank maintenance person. It’s very obvious that something in your water quality is wrong or the testing method is. Do you test yourself or only your LFS. What water are you using to top off the tank? It maybe possible that there’s something in your water that is toxic if not using RO/DI water. I would recommend not adding anymore fish until you make sure that water quality is good and your know for sure that ro/di water is used for top off.

 

[albano]

She was even skeptical that the serpent star was a problem, but others at the LFS thought it could be hunting. either way, deaths are still occurring.

What color serpent star?

 

[exnisstech]

 

[Torps]

Looking at your picture and how you tank looks like, I’d question your “professional” tank maintenance person. It’s very obvious that something in your water quality is wrong or the testing method is. Do you test yourself or only your LFS. What water are you using to top off the tank? It maybe possible that there’s something in your water that is toxic if not using RO/DI water. I would recommend not adding anymore fish until you make sure that water quality is good and your know for sure that ro/di water is used for top off.

I’ve got an RO drinking system at home and have done quite a bit of research on it, so I know what a RO/DI system should LOOK like (heavy emphasis on “look”). They’ve got a monster setup. If they’re not actually making RO/DI, they’re going the extra mile to scam everyone.

What about my tank is a flash for you? It used to be more appealing, but I tore it up pretty good catching the shrimp. She makes rearranging look allot easier than it is. When I inherited it, the previous owner was “chemical” adverse, so there was quite a bit of red growth. That’s toned down vastly, but there’s still some rust color in the sand. That is new live sand as of a year ago when I moved the tank.

It was a plain black serpent star. His behavior definitely changed when the grama was introduced. He started “tenting” over the grama’s hiding nook.

 

[Damage12]

Where in FL are you? Who is your LFS?

 

[Subsea]

Looking at your picture and how you tank looks like, I’d question your “professional” tank maintenance person. It’s very obvious that something in your water quality is wrong or the testing method is. Do you test yourself or only your LFS. What water are you using to top off the tank? It maybe possible that there’s something in your water that is toxic if not using RO/DI water. I would recommend not adding anymore fish until you make sure that water quality is good and your know for sure that ro/di water is used for top off.

@Torps
After looking at your substrate, I don’t consider this to be professionally maintained, unless the service is very cheap. Also, I don’t think that zero nitrate is a good thing. What test kit are you using to check your phosphate ppm? Opportunistic algae, Dinoflagellates when deprived of phosphate & nitrate become toxic. Snails and other herbivores would die first.

In an earlier post, you said that you inherited “red growth”. Would that be Cyanobacteria?

“It was a plain black serpent star. His behavior definitely changed when the grama was introduced. He started “tenting” over the grama’s hiding nook.“

Green serpent star were well known for that behavior. While I never saw any capture, I did loose small fish, until I transferred him.

 

[Torps]

Where in FL are you? Who is your LFS?

I don’t want to dox them quite yet.

After looking at your substrate, I don’t consider this to be professionally maintained, unless the service is very cheap. Also, I don’t think that zero nitrate is a good thing. What test kit are you using to check your phosphate ppm? Opportunistic algae, Dinoflagellates when deprived of phosphate & nitrate become toxic. Snails and other herbivores would die first.

In an earlier post, you said that you inherited “red growth”. Would that be Cyanobacteria?

I use an API test kit. Some tests use two bottles, 5-10 drops each. Not sure of different types… thought they were all about the same. Thanks, I’ll do some reading about all this!

99.8% sure the red stuff wasn’t cyano. It was red but had no other indication. I spent tons of time reading about that.

 

[Subsea]

I don’t want to dox them quite yet.

I use an API test kit. Some tests use two bottles, 5-10 drops each. Not sure of different types… thought they were all about the same. Thanks, I’ll do some reading about all this!

99.8% sure the red stuff wasn’t cyano. It was red but had no other indication. I spent tons of time reading about that.

After 55 years as a reefer, I am the last person to evaluate test kits. I have unopened test kits with expired dates. However, as a former lab technician, shades of color to determine concentration is not very precise, especially in the low range of parts per billion which is where phosphate runs. On a wild reef, inorganic phosphate & nitrate are in the PPB and are utilized miniscully: DOC, Dissolved Organic Carbon, and POC, Particulate Organic Carbon, are food for corals.
However, in our captive reefs, depending on what we feed, measurable phosphate & nitrate are necessary.

“99.8% sure the red stuff wasn’t cyano. It was red but had no other indication. I spent tons of time reading about that”

What do you think the red stuff was? Any pictures?
I noticed that you show Florida as your location.
Have you witnessed a “Red Tide”

https://myfwc.com/research/redtide/statewide/

 

[Damage12]

I don’t want to dox them quite yet.

I use an API test kit. Some tests use two bottles, 5-10 drops each. Not sure of different types… thought they were all about the same. Thanks, I’ll do some reading about all this!

99.8% sure the red stuff wasn’t cyano. It was red but had no other indication. I spent tons of time reading about that.

No, worries. I used to be in the business and wanted to give you an idea if I know them and if they are reputable.

Avoid API test kits, they’re garbage. If your LFS is picking up fish for you direct from a wholesaler and adding them to your tank, I would question the quality of fish they are choosing and would not continue doing that.

What area in FL? Maybe I can steer you toward a better store.

 

[larrysaltisfun]

Maybe buy your fish from a pre- quarantined online dealer like Dr Reef

I may have missed it in previous posts but if your LFS is keeping fish at low salinity they are potentially masking problems like ICH and velvet

I would also do an ICP on your salt water and your RODI water

 

[Mchava]

The biggest issue i see is all that green filament algae all over your rocks and back wall and what looks like some type of algae on you sandbed. You even have it growing on your overflow. This leads me to think that your water source it the issue. As other have mention you need better test kit. If your tank was set up a year ago it should not look that way unless you've had poor husbandry and upkeep.

 

[mmorrison55]

If you are in the Tampa Bay Area, I can recommend “Fish and other Ichthy stuff” as a good place to buy healthy fish. He doesn’t do a full QT,but he’s about as close to it as you will get in the area. Some nearby fish stores get their fish in and in their sell tanks the same day.

 

[mmorrison55]

Ive had good results online with dr reefs as well.

Maybe send a sample off for an icp test to see if you have high metal content.

Any magnets in the tank that could have rusted and leached into your tank? You mentioned inheriting it over a year ago, so possible some old equipment is your culprit.

 

[Freenow54]

I read through all the replies . I had not seen anything to give me concern , but I am not an expert. I too have lost 6 of my 7 fish . The list ? Aggression # 1 Happens in the dark mostly . chasing out of tank/ straight up body butting / Have you ever heard the term worried to death ? Seen it with my own eyes fish , and mammals. # 2 Feeding bad food . Lost one that way . Surprising them and they injure themselves . My latest just hibernated in a small dark place ( a 4 year old yellow watchman Goby . I could not observe it . This all happened to me. MY SUPRISE WAS THAT NO ONE COMENTED ON THE DISMAL STATE OF YOUR SUBSTRATE . AT LEAST TO ME. Could that be leaking Sulphur dioxide ? Which I have read about ? I am Asking you all.

 

[Freenow54]

I've lost multiple fish and subsequently evicted the CBS and Serpent Star to remove all possible predators. Since then, I lost a fire fish (lived one day) and a clown fish (lived 3 weeks). The tank is professionally maintained and water quality is pristine. The current residents are a Pajama Cardinal which has survived the entire year since I inherited the tank, and a Royal Grama that's lasted a month. There's several corals and snails and such, but absolutely nothing that's remotely dangerous toward fish.

I figure there's either a large bobbit worm (or other predator) that somehow went unnoticed during the move a year ago, or stray voltage. Anyone have any tips? I'm not too keen on spending hundreds in fish just to have them all die. I have zero reasons to suspect either of these problems, but I'm at a loss for a fix. I'd love a solid lead on this... I'm about ready to redirect my hobby budget and time elsewhere

Stray voltage "test results" below. No clue how to interpret them.
one lead in water, other free in air: 8V
complete circuit, no equipment plugged in: 12V
one piece of equip plugged in (doesn't matter what): 45V
each additional piece of equip (any order): +5V

Another Thought I had not intending to insult anyone but... Is your professional adding any chemicals to fight/ prevent disease ?

 

[Torps]

After 55 years as a reefer, I am the last person to evaluate test kits. I have unopened test kits with expired dates. However, as a former lab technician, shades of color to determine concentration is not very precise, especially in the low range of parts per billion which is where phosphate runs. On a wild reef, inorganic phosphate & nitrate are in the PPB and are utilized miniscully: DOC, Dissolved Organic Carbon, and POC, Particulate Organic Carbon, are food for corals.
However, in our captive reefs, depending on what we feed, measurable phosphate & nitrate are necessary.

“99.8% sure the red stuff wasn’t cyano. It was red but had no other indication. I spent tons of time reading about that”

What do you think the red stuff was? Any pictures?
I noticed that you show Florida as your location.
Have you witnessed a “Red Tide”

https://myfwc.com/research/redtide/statewide/

Here are pics from June 2025, about two weeks after the move not sure why one is so red and another is not. I also forgot how small those corals used to be. CBS molted close to half a dozen times since this pic too.

No, worries. I used to be in the business and wanted to give you an idea if I know them and if they are reputable.

Avoid API test kits, they’re garbage. If your LFS is picking up fish for you direct from a wholesaler and adding them to your tank, I would question the quality of fish they are choosing and would not continue doing that.

What area in FL? Maybe I can steer you toward a better store.

They keep and treat the fish for several days before selling. They don’t just drop-ship thin.

Maybe buy your fish from a pre- quarantined online dealer like Dr Reef

I may have missed it in previous posts but if your LFS is keeping fish at low salinity they are potentially masking problems like ICH and velvet

I would also do an ICP on your salt water and your RODI water

Ive had good results online with dr reefs as well.

Maybe send a sample off for an icp test to see if you have high metal content.

Any magnets in the tank that could have rusted and leached into your tank? You mentioned inheriting it over a year ago, so possible some old equipment is your culprit.

I’ll get a new magnet cleaner just in case! I’ll get a water test too. I’ve done that for oil, but never thought of it for a reef tank!

Another Thought I had not intending to insult anyone but... Is your professional adding any chemicals to fight/ prevent disease ?

No chemicals for disease.

 

[Damage12]

Here are pics from June 2025, about two weeks after the move not sure why one is so red and another is not. I also forgot how small those corals used to be. CBS molted close to half a dozen times since this pic too.

They keep and treat the fish for several days before selling. They don’t just drop-ship thin.



I’ll get a new magnet cleaner just in case! I’ll get a water test too. I’ve done that for oil, but never thought of it for a reef tank!

No chemicals for disease.

Treating the fish for several days is not enough. That is not even close to a full “treatment”, whatever they are doing and I’m not even big on quarantining myself.

I would recommend getting a better service company/fish store to purchase from (not that I think you need one with a tank that size…..if you want it done right, do it yourself).

Just ask here for recommendations in your area and I’m sure plenty of people will provide good suggestions. I don’t think you told us what town or county you are near in FL.

Best of luck to you.

 

[mmorrison55]

If it’s your magnet cleaner, you would know, it would be swollen and you would see a seem exposed.

I was more thinking about heater element holders or wavemaker holders or even return pumps that a lot of times has a magnet that goes on the inside of the tank or sump and if you are not removing it regularly to clean could have gotten exposed to water and the magnet inside could have started to rust.

I would pull all mechanical devices installed inside your tank out one by one, clean and inspect all the seams and look for any signs of rust etc.

Ive seen pics of wave maker or return pumps impeller shafts covered in rust, So it can be in the most inconspicuous spot and easily go unnoticed.

If nothing else, you’d have done your upkeep main and should be good for the next 6 mos or a year before needing to do it again.

Good luck, I can imagine this has been very frustrating for you.

 

[Subsea]

In looking at your pervious picture with red algae on substrate, why are you 99.8% sure it’s not Cyanobacteria, because that is what it looks like to me.

 

[mcarroll]

I've lost multiple fish

Definitely a bummer that most folks here can relate to.

Can you tell us about the tank?

How old?

Was it set up with live rock or dead?

What filter equipment?

A picture of the tank would help fill in the gaps.

Also the fish, maybe start with the most recent loss. What was the fish and how did it pass? Please be detailed with symptoms.