Losing Fish 1 by 1 / Need Help

Drew Shark · Sep 19, 2023

Hi. Unfortunate first post. I have been in the hobby since 2010. I have never encountered something like this.

I have now lost 2 of my prized fish over the past week. First was a fat 5+ inch Achilles Tang. I had him for over a year and a half. Died 5 days ago. I was really bummed. Tonight my coral cat shark female died. She was about 15 inches. I had her for several months. The fish each were swimming and then died within 2 hours. No wounds visible. No diseases visible. Just swimming. Lay down on the sand bed. Dead.

1. My suspicion is that NOPOX at 45mL a day is too high. However I have been at this level for months now. Nitrate will not drop. Phosphate stays the same. Phosphate is measurable as Hanna ULR says out of range. So it is there. I am wondering about O2 depletion? Or CO2 buildup? However there is surface agitation. Water crashing in sump. 2x Protein skimmers. Room windows are always open year round. I live in coastal Southern California.

2. My second guess is nitrate toxicity. With 100+ ppm NO3 for at least a year, I am guessing it wore the fish down? Corals are also so-so for a long time. Kenya trees are happy. My sinularia is not. Multiple colonies of each. The weird thing is the sinularia perks up when I feed Benereef occasionally. Old school polyps (Palythoas sp.) are spreading. So inconclusive.

3. Microbiome imbalance? This might explain NO3 and PO4 not dropping. I also only have to clean the glass 2x weekly. It is a pretty thin film of brown. Not much. There is also an absence of Coraline algae growth. Not much growth on rocks. I started with Marco Rocks 150 pounds.

4. Perhaps not enough nutrient export? Both skimmers which should each be capable of my system produce skim mate. But it is light brown watery liquid. It stinks. But not sludge. I try and aim for a more liquid product due to running NOPOX. I empty and clean the cups maybe every 2 weeks.

I use RODI produced by me. 0 TDS. I have not done a water change in a long time.

The tank has been running for about 3 years now.

Fish left:
2x percula clowns
1x green chromis
1x yellow tang 5+ years old with me
1x tomini tang
2x Purple Queen Anthias (3+ months with me. Eat pellets)
1x Multibar Angel
1x Watanbei angel female.

The facts:
150 gallon display 5x2x2
10 gallon mangrove tank
45 gallon sump
Probably 180+ gallon total water volume

Parameters (Salifert that expire in 1-2 years from today.):
Alk 8.0 dKH
NO3 100+ ppm (off the charts)
PO4 0.25 ppm

Temp 80
pH 8.3 per Apex

Dosing:
All-for-reef 28mL / day
NOPOX 45mL / day

Equipment:
2x Reef octopus 202s protein skimmers
2x ETM MP40mQD on ReefCrest 100%
Multiple cups ROX 0.8 carbon
Filter pad at drains for sump. Changed every 36 hours.
3x NICREW HyperReef LEDS 100w for display. 100% for 11 hours.

Turnover is medium. Running a JEBAO DCP15000 100% to display tank. 1 inch return line to 2x 3/4" loc-line at the water surface.

Mangrove tank is a separate circuit off of the sump. With JEBAO DCP3500 100% . Two 3+ foot red mangroves. A lot of leaves and branches.

blaxsun · Sep 19, 2023

#fishmedic

fishguy242 · Sep 19, 2023

hi welcome to the reef,
any signs of distress on other fish ?
wait for the experts ,my suggestions would be 40 gal water change and fresh rinsed carbon
if not seeing any signs on other fish .

MnFish1 · Sep 19, 2023

Have you added any new fish? I'm assuming your fish really had no spots, breathing issues, etc. When a fish does what you describe - it sounds like a toxic issue - or oxygen/nitrate. I doubt a CO2 issue if your pH, and alkalinity are what your measurements say they are. It's a bit confusing how you can have such a high nitrate with as much export going on as you have - are you overfeeding, etc? I would think water changes to get your nitrate down to more 'normal' levels would also help with anything else that might be in the water.

PS - I would also verify your tests and procedures to be sure that your nitrate is really 100+. You can determine the actual nitrate by diluting the water. For example take 10 cc of tank water and 10 cc of newly mixed salt water. Assuming that there is no nitrate in the new water, you do the test as you normally would - and then double the result. Example if the nitrate level in the diluted sample is 75, your nitrate is 150 ppm

Drew Shark · Sep 19, 2023

To answer some questions:
1. I have seen ich and velvet in previous tanks. This is not evident in this case. No white spots, flecks, increased mucus, etc...
2. Both fish were totally fine before death. Eating, swimming, pooping. No increased respiration rate noticeable.
3. The high nitrate is confusing to me as well.
4. Feeding most recently has been throughout the day. Includes: 2x cubes PE mysis, Prime Reef flake (1 pinch), TDO small(C1) and B2 sizes (less than a 1/2 teaspoon total/day). Enriched with a squirt of Selcon.
5. I don't understand where all my nutrients are coming from as well.
6. Just added a poly filter pad to the mechanical filtration. Hopefully it absorbs something....
7. I will test nitrate with diluted sample and report back. I need to make NSW. Give me some time.
8. ROX 0.8 carbon was last switched a week ago. I run probably close to 4 cups in mesh bags next to return pump.

Overall, the toxin idea is interesting in my mind. However, other sensitive animals in the same room are okay. Poison dart frogs, sensitive reptiles (Phelsuma ornata), and a leopard gecko who is 15 are good. I (human) and my dogs and cats in the house are ok.

One question is what about NO3/PO4 imbalance? I am reasonably confident in my tests. So if nitrate is 100ppm and PO4 is 0.25ppm, should PO4 not be higher? Are there repercussions for this?

Thank you for the help.

MnFish1 · Sep 19, 2023

Drew Shark said:
To answer some questions:
1. I have seen ich and velvet in previous tanks. This is not evident in this case. No white spots, flecks, increased mucus, etc...
2. Both fish were totally fine before death. Eating, swimming, pooping. No increased respiration rate noticeable.
3. The high nitrate is confusing to me as well.
4. Feeding most recently has been throughout the day. Includes: 2x cubes PE mysis, Prime Reef flake (1 pinch), TDO small(C1) and B2 sizes (less than a 1/2 teaspoon total/day). Enriched with a squirt of Selcon.
5. I don't understand where all my nutrients are coming from as well.
6. Just added a poly filter pad to the mechanical filtration. Hopefully it absorbs something....
7. I will test nitrate with diluted sample and report back. I need to make NSW. Give me some time.
8. ROX 0.8 carbon was last switched a week ago. I run probably close to 4 cups in mesh bags next to return pump.

Overall, the toxin idea is interesting in my mind. However, other sensitive animals in the same room are okay. Poison dart frogs, sensitive reptiles (Phelsuma ornata), and a leopard gecko who is 15 are good. I (human) and my dogs and cats in the house are ok.

One question is what about NO3/PO4 imbalance? I am reasonably confident in my tests. So if nitrate is 100ppm and PO4 is 0.25ppm, should PO4 not be higher? Are there repercussions for this?

Thank you for the help.

Thanks for the information. When I meant a 'toxic issue' - I meant nitrate or O2 or something else thats not measured in your tank. IF your nitrates are 'correct' - they are really too high - and whether showing it or not your fish etc are probably not doing as well as they could be. I do not know that you can say for sure whether the Po4 should be higher, etc - since we really don't know the level of nitrates - but - generally they can also be independent of one another.

00W · Sep 19, 2023

How big is the room all that stuff is in?
Possible and wondering what might be transferring over airborne from reptiles, etc.to tank.
Just a thought.

Drew Shark · Sep 19, 2023

1. Tested NO3 again. Salifert. This time I did a 10-1 dilution with RODI water. Nitrate came out to exactly 100ppm as the final result. So luckily not 100+. Just 100ppm flat.
2. The room is 160 SQFT.
3. The reptiles and tank have been together since the beginning. So no changes there. All the reptiles are in bioactive enclosures. So no chemicals used.
4. I think I am going to buy a Hanna Nitrate High Range meter. Just to check on things.

EeyoreIsMySpiritAnimal · Sep 19, 2023

Drew Shark said:
I have not done a water change in a long time.

Do a large water change (or 2) asap to get the nitrates down. Phosphates look great.

mikerosi · Sep 19, 2023

EeyoreIsMySpiritAnimal said:
Do a large water change (or 2) asap to get the nitrates down. Phosphates look great.

Just to verify, your phosphates are .25, correct

EeyoreIsMySpiritAnimal · Sep 19, 2023

mikerosi said:
Just to verify, your phosphates are .25, correct

He said they were 0.25 which is fine with a nitrate level of 20-50. First step, do the easy thing and dilute the nitrates with water changes. Then if he wants to lower both N and P, there are ways to do that in tandem (although I run N at 50 and phos at .75-1.0 and have no problems)

Drew Shark · Sep 19, 2023

Yes. PO4 is 0.25ppm per Salifert.

Drew Shark · Sep 19, 2023

A question why everyone is here: Why is 45 mL a day of NOPOX not lowering my NO3? That is almost double Red Sea's instructions for FOWLR. I have been measuring 100ppm NO3 for more than 3 months per my log. I have been using NOPOX since near the beginning of this tank. So 3+ years.

vetteguy53081 · Sep 19, 2023

Drew Shark said:
A question why everyone is here: Why is 45 mL a day of NOPOX not lowering my NO3? That is almost double Red Sea's instructions for FOWLR. I have been measuring 100ppm NO3 for more than 3 months per my log. I have been using NOPOX since near the beginning of this tank. So 3+ years.

I would first verify you are getting accurate readings then have a second test by taking a water sample to an LFS that does not use Api kits and see what readings they get and to compare with yours.
Thats a lot of NOPOX which is vinegar dosing and may or may not have had an impact on your fish.
Its often and alternative and not a solution. Change 30% of your water and 2 gals a day for 2 weeks and No3 should drop for sure

EeyoreIsMySpiritAnimal · Sep 19, 2023

Drew Shark said:
I have been measuring 100ppm NO3 for more than 3 months per my log

Water change

00W · Sep 19, 2023

Just wondering on the room is all. Weird things happen. My buddy lost a whole tank once when they repainted his downstairs. And he was careful.
Get rid of the nopox. Doing no good anyways.
Large water change but not too drastic.
For fun,if you have a reactor, fill it with denitrate and run it about 10 gallons an hour. Works for me.
As mentioned above, daily smaller water changes will really help.
Not every product works on every tank.

duanejon · Sep 19, 2023

100 ppm nitrate is pretty high. The more sensitive fish can get stressed out with nitrates over 50 ppM. However it is generally nitrites that will kill the fish. Have you had that tested ?

EeyoreIsMySpiritAnimal · Sep 19, 2023

duanejon said:
100 ppm nitrate is pretty high. The more sensitive fish can get stressed out with nitrates over 50 ppM. However it is generally nitrites that will kill the fish. Have you had that tested ?

Um, no.
You're looking for the freshwater forum.