Lost 4 fish in 2 days only one still alive, need advice.

[RobertT]

This is my first post on here so let me pre apologize

Let me say first, this is not my first rodeo. But I have never encountered this problem before. I had a 90g reef 20g sump for 5yrs, upgraded to 8' long 110g rimless shallow reef+ 40g sump which broke flooding my house ending the reefing hobby for me 4yrs ago. Now, I'm back baby! Or so I thought. I set up a 55g tank to ease back into the hobby 2 months ago. The setup is simple, Seachem Tidal 75 HOB with filter pad Seachem de-nitrate media, Phosguard, carbon from Petco, 100g rated HOB protein skimmer and 2 Hydor powerheads for flow. Livestock, 1 coral beauty, 2 Ocellaris clowns, 1 Falco hawkfish, 1 carpenter wrasse, 2 peppermint shrimp, 11 snails and 2 anemones 1 Rose and 1 Condy. No coral yet. Tank water comes from LFS who uses Red Sea Salt brand.

A couple of days ago on Thurs, Fish looked healthy, active and eating. Fri morning find the coral beauty dead, all the other livestock looked fine. Today(Sat) wakeup to find both clowns and wrasse dead. The hawkfish, shrimp, snails, and anemones look fine.
Tested the water salinity 1.025, 0 ammonia, 0 nitrites, nitrates are well under 20ppm, GH between 7.5-8.0 (low, but not enough to hurt fish), BUT, the KH was testing at 20-40ppm or about 2.0-3.0 which dumbfounded me. I just did a 25-30% (15gal) water change on Mon. So I took a sample of my water to my LFS today(Sat) who confirmed my results, said the fish are only dying at night because the KH is dropping too low after dark. He said the carbon and Phosguard are probably the cause, sucking the alkalinity out the water. He said another water change won't help and he sold me Red Sea B/KH to dose at 20mil a day till I reach normal levels. I removed the carbon and Phosgard from my filter also.

Does this sound right? I had always used carbon and GFOs in the past and never had a KH issue that killed fish. The only difference from then and now is salt brand, then I used Instant Ocean but now I'm using Red Sea. Any advice will be much appreciated, I would love to add that first coral but first I have to keep the fish alive.

 

[Musovski]

Did you acclimate? Also, the hawkfish are aggressive fish... just saying.

 

[RobertT]

Did you acclimate? Also, the hawkfish are aggressive fish... just saying.

The hawkfish was not aggressive to the other fish or (surprisingly) the peppermint shrimp

 

[Dan_P]

This is my first post on here so let me pre apologize

Let me say first, this is not my first rodeo. But I have never encountered this problem before. I had a 90g reef 20g sump for 5yrs, upgraded to 8' long 110g rimless shallow reef+ 40g sump which broke flooding my house ending the reefing hobby for me 4yrs ago. Now, I'm back baby! Or so I thought. I set up a 55g tank to ease back into the hobby 2 months ago. The setup is simple, Seachem Tidal 75 HOB with filter pad Seachem de-nitrate media, Phosguard, carbon from Petco, 100g rated HOB protein skimmer and 2 Hydor powerheads for flow. Livestock, 1 coral beauty, 2 Ocellaris clowns, 1 Falco hawkfish, 1 carpenter wrasse, 2 peppermint shrimp, 11 snails and 2 anemones 1 Rose and 1 Condy. No coral yet. Tank water comes from LFS who uses Red Sea Salt brand.

A couple of days ago on Thurs, Fish looked healthy, active and eating. Fri morning find the coral beauty dead, all the other livestock looked fine. Today(Sat) wakeup to find both clowns and wrasse dead. The hawkfish, shrimp, snails, and anemones look fine.
Tested the water salinity 1.025, 0 ammonia, 0 nitrites, nitrates are well under 20ppm, GH between 7.5-8.0 (low, but not enough to hurt fish), BUT, the KH was testing at 20-40ppm or about 2.0-3.0 which dumbfounded me. I just did a 25-30% (15gal) water change on Mon. So I took a sample of my water to my LFS today(Sat) who confirmed my results, said the fish are only dying at night because the KH is dropping too low after dark. He said the carbon and Phosguard are probably the cause, sucking the alkalinity out the water. He said another water change won't help and he sold me Red Sea B/KH to dose at 20mil a day till I reach normal levels. I removed the carbon and Phosgard from my filter also.

Does this sound right? I had always used carbon and GFOs in the past and never had a KH issue that killed fish. The only difference from then and now is salt brand, then I used Instant Ocean but now I'm using Red Sea. Any advice will be much appreciated, I would love to add that first coral but first I have to keep the fish alive.

I am sorry to hear of your loss.

Fish dying at night sounds like low oxygen levels, i.e., they suffocated.

 

[RobertT]

I am sorry to hear of your loss.

Fish dying at night sounds like low oxygen levels, i.e., they suffocated.

Wouldn't the oversized protein skimmer and all the surface agitation from powerheads and oversized HOB filter with surface skimmer provide enough oxygen? What would cause the oxygen to drop at night and not affect the fish during the day?

 

[Dan_P]

Wouldn't the oversized protein skimmer and all the surface agitation from powerheads and oversized HOB filter with surface skimmer provide enough oxygen? What would cause the oxygen to drop at night and not affect the fish during the day?

I mention it as a possibility for your consideration.

Increased respiration of O2 is the effect of no lights on anything that derives energy from photosynthesis in the system. While a bacterial bloom consumes oxygen day and night, it combined with the increased respiration of photosynthesizers might be enough to cause a problem.

 

[RobertT]

I mention it as a possibility for your consideration.

Increased respiration of O2 is the effect of no lights on anything that derives energy from photosynthesis in the system. While a bacterial bloom consumes oxygen day and night, it combined with the increased respiration of photosynthesizers might be enough to cause a problem.

I understand your intentions, I'm not arguing or saying you're wrong. I question only to understand and utilize the process of elimination.
Would I be able to see a bacterial bloom? My tank has no visible algae outside of some little leftover diatoms due to my conservative clean-up crew, the water is crystal clear and no film on the glass. Fish tend to move to the top of the tank in a low oxygen environment and become less active, I didn't witness this behavior. Fish active eating and normal all-day. I have keep aquariums for the last 15+ years. I currently have 6 running a 10yr old 20gal fresh live plant , 29gal live plant brackish, 20gal fresh live plant snail breeder, 10gal fresh live plant shrimp only, 13.5gal salt and my 55gal reef attempt. I have kept 20gal, 90gal and 110gal reefs in the past. I have never experienced fish dying from low oxygen even in my most overstocked tanks. So this idea is new to me, I mean I've heard of it but I've never experienced it.
Till now, maybe?

 

[Dan_P]

I understand your intentions, I'm not arguing or saying you're wrong. I question only to understand and utilize the process of elimination.
Would I be able to see a bacterial bloom? My tank has no visible algae outside of some little leftover diatoms due to my conservative clean-up crew, the water is crystal clear and no film on the glass. Fish tend to move to the top of the tank in a low oxygen environment and become less active, I didn't witness this behavior. Fish active eating and normal all-day. I have keep aquariums for the last 15+ years. I currently have 6 running a 10yr old 20gal fresh live plant , 29gal live plant brackish, 20gal fresh live plant snail breeder, 10gal fresh live plant shrimp only, 13.5gal salt and my 55gal reef attempt. I have kept 20gal, 90gal and 110gal reefs in the past. I have never experienced fish dying from low oxygen even in my most overstocked tanks. So this idea is new to me, I mean I've heard of it but I've never experienced it.
Till now, maybe?

Check out this Interesting study by Borneman. The information might be useful in your search for answers.

http://reefkeeping.com/issues/2005-08/eb/index.php

 

[RobertT]

Check out this Interesting study by Borneman. The information might be useful in your search for answers.

http://reefkeeping.com/issues/2005-08/eb/index.php

Thank you,
Using that study I was able to rule out low oxygen as the cause of death. Being my reef has no coral yet or an algae problem and I'm running a protein skimmer 2X larger than needed my tank should have high oxygen saturation after lights out according to their study. Their low oxygen results were based on a heavily coral stocked tanks with (I assume) an undersized protein skimmer, they say "small" but don't specify size and NO skimmer at all. And the tank with an adequate protein skimmer or air stone held consistent oxygen saturation all night.
The guy at my LFS was able to describe in great detail how my low KH killed the fish. He described how long it takes them to die, their behavior before(daytime) and up to(nighttime) death and the stages of how a fish's body shuts down in low KH in medical jargon, I pretended to understand, lol.

 

[Dan_P]

Thank you,
Using that study I was able to rule out low oxygen as the cause of death. Being my reef has no coral yet or an algae problem and I'm running a protein skimmer 2X larger than needed my tank should have high oxygen saturation after lights out according to their study. Their low oxygen results were based on a heavily coral stocked tanks with (I assume) an undersized protein skimmer, they say "small" but don't specify size and NO skimmer at all. And the tank with an adequate protein skimmer or air stone held consistent oxygen saturation all night.
The guy at my LFS was able to describe in great detail how my low KH killed the fish. He described how long it takes them to die, their behavior before(daytime) and up to(nighttime) death and the stages of how a fish's body shuts down in low KH in medical jargon, I pretended to understand, lol.

I might check up on the low KH theory killing the fish. KH should not be dropping that much overnight. And didn’t you mention that you bought the water from the LFS?

The entire explanation as you describe it does not seem like a plausible. Of course, you may never find the cause.

 

[jaxredsoxfan]

These are the worst kind of emergencies, when a cause isn't readily identified. I would just monitor parameters, and wait a bit to see what develops. Once again sorry for your loss.

 

[Jay Z]

These are the worst kind of emergencies, when a cause isn't readily identified. I would just monitor parameters, and wait a bit to see what develops. Once again sorry for your loss.

Hate these situations too, sometimes its like asking why the tornado hit this and not that. Very frustrating.

 

[Dkeller_nc]

It's quite hard to explain why your alkalinity would be that low with a specific gravity of 1.025. Since you mention that the tank water comes from the LFS, I'd test it. If you get an answer that's less than about 6 dKH, then I'd strongly suspect that the specific gravity isn't really 1.025. It is true that phosphate absorbing media can remove alkalinity from tank water by causing the precipitation of calcium carbonate on the media's surface, but this effect is typically fairly minor in a large tank unless you're running a great deal of media.

The symptoms you're describing actually suggest a disease process to me - specifically, marine velvet, which can kill fish in 24 hours. One specific reason that I suspect this is that you've not lost any of the inverts, which would be a great deal more sensitive to water chemistry parameters than fish.

 

[ZachR32]

When was the most recent fish added? Unless your QTing I would suspect disease before anything else

 

[RobertT]

I might check up on the low KH theory killing the fish. KH should not be dropping that much overnight. And didn’t you mention that you bought the water from the LFS?

The entire explanation as you describe it does not seem like a plausible. Of course, you may never find the cause.

My KH test yesterday morning (after lights on) was showing less than 2 or 20-40ppm which is well under the recommended 8 or 120-240ppm. This morning it's a little higher after dosing yesterday. My LFS claims they test every batch of water and their water tests at 9 KH. Are they lying or a bad batch of salt? Or, is my media really sucking the alkalinity out my tank? I've heard CO levels in a room can cause KH to drop, but my tank is in a large open room with 2 doors constantly opening letting fresh air in all-day.

 

[RobertT]

It's quite hard to explain why your alkalinity would be that low with a specific gravity of 1.025. Since you mention that the tank water comes from the LFS, I'd test it. If you get an answer that's less than about 6 dKH, then I'd strongly suspect that the specific gravity isn't really 1.025. It is true that phosphate absorbing media can remove alkalinity from tank water by causing the precipitation of calcium carbonate on the media's surface, but this effect is typically fairly minor in a large tank unless you're running a great deal of media.

The symptoms you're describing actually suggest a disease process to me - specifically, marine velvet, which can kill fish in 24 hours. One specific reason that I suspect this is that you've not lost any of the inverts, which would be a great deal more sensitive to water chemistry parameters than fish.

All my fish have been in the tank together over a month. My SG was tested 3 times with 3 different brand tools and was consistent. The KH was tested with 2 different brand test kits.
Are Falco Hawkfish immune? Marine velvet is visible, my fish had no signs of it or ich like symptoms. I don't know of disease that targets a specific time of day to cause death between 12 am an 5 am

 

[Dkeller_nc]

Then that's truly odd. Alkalinity, of course, will fall gradually in a saltwater tank through various biological and abiological processes, so a low alkalinity would be expected if one set up a tank and didn't do any water changes over a long period of time. And it's also true that water changes will not "keep up" with alkalinity demand in a tank with significant amounts of coralline algae or with a high bioload and a lot of feeding (ammonia oxidation to nitrate consumes alkalinity).

But it doesn't appear that's the case here, unless you set up the tank 2 months ago per your original post but didn't do significant water changes, especially after the tank nitrogen cycle (if you set it up with dry rock).

 

[RobertT]

Then that's truly odd. Alkalinity, of course, will fall gradually in a saltwater tank through various biological and abiological processes, so a low alkalinity would be expected if one set up a tank and didn't do any water changes over a long period of time. And it's also true that water changes will not "keep up" with alkalinity demand in a tank with significant amounts of coralline algae or with a high bioload and a lot of feeding (ammonia oxidation to nitrate consumes alkalinity).

But it doesn't appear that's the case here, unless you set up the tank 2 months ago per your original post but didn't do significant water changes, especially after the tank nitrogen cycle (if you set it up with dry rock).

I did no water changes until the tanks cycle was complete, followed by a 40%(20gal) water change then 20-25%(10-15gal) every week after.
Day the tank setup I put a healthy dose of frozen brine to spike ammonia followed by an entire 250ml bottle of Bio-Spira a week after. 3rd week the tank was covered in diatoms, ammonia, nitrite was 0. 4th-week ammonia and nitrites was still 0. End of 4th week 40% water change and anther bottle of Bio-Spira, carbon, and Phosguard was added followed by the livestock.
According to my LFS you're supposed to dose KH when using any type of GFO media because GFO will dramatically lower KH in a short time span. And none reef specific carbon will lower KH faster. Which is why his store uses no carbon or GFO in their tanks. I did not know this.
I've pulled my carbon and GFO and have been dosing KH. My KH is back to normal(120ppm) my Hawkfish still alive and trying to eat up all my copepods. My Anenomes, shrimp, and snails look happy. My rose bulb has tripled in size and my Condy has doubled in the past month.
It seemed odd to me because I have used GFO in the past without dosing KH and had no problems, but this is the first time I've used Seachem's Phosguard and cheap Petco carbon.

 

[aqua_code]

I've used GFO many times with no ill effects on the fish - However, SPS corals are a different story. Also - did you wash your GFO before use?

I agree with the previous posts that say it's disease or a parasite. The LFS water can have ich or parasites that can cause these problems. You can really only remove 99.99% of their water and that .01% can be infected. A fish can also be infected when you purchase them. It's possible a parasite was transferred in an early part of the lifecycle and took 2 months to develop into a full blown problem. I usually run a new tank without fish for 79 days when introducing any shrimp, macroalgae (because a single drop of water can host ich!).

The fish stay in quarantine and are treated with general cure to kill any internal or external parasites. Afterwards they are treated with copper and observed to ensure proper health. Skipping this process can introduce all kinds of unwanted problems.

Sorry for your losses. I recommend strict quarantine procedures to ensure this doesn't happen in the future.

 

[RobertT]

I've used GFO many times with no ill effects on the fish - However, SPS corals are a different story. Also - did you wash your GFO before use?

I agree with the previous posts that say it's disease or a parasite. The LFS water can have ich or parasites that can cause these problems. You can really only remove 99.99% of their water and that .01% can be infected. A fish can also be infected when you purchase them. It's possible a parasite was transferred in an early part of the lifecycle and took 2 months to develop into a full blown problem. I usually run a new tank without fish for 79 days when introducing any shrimp, macroalgae (because a single drop of water can host ich!).

The fish stay in quarantine and are treated with general cure to kill any internal or external parasites. Afterwards they are treated with copper and observed to ensure proper health. Skipping this process can introduce all kinds of unwanted problems.

Sorry for your losses. I recommend strict quarantine procedures to ensure this doesn't happen in the future.

I know with 100% certainty my alkalinity was tanking below safe levels at night during the time of death which is why the bigger fish died the first night and the smaller fish die the second night when the alkalinity had dropped lower than the night before.
I have talked to another who has experienced the issue and witnessed fish dying from low alkalinity in his client's tanks over the years.
Disease and parasites like ick or marine velvet are visible and or have telltale signs. My fish were active, eating smiling at bedtime then dead in the morning with no visible cause. All my fish died at a specific time of the night, parasites or disease don't pick a specific time of day to kill.
Just as low alkalinity can be harmful to humans it can be fatal to fish.