Mass fish deaths

Bgk86

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Freshwater fish constantly dying!

Hi all. New to posting on this forum but have been following threads for quite some time. I've been keeing fish for some 20 years.

Parameters.
Tank
75gal. Cycled for 2 months fishless cycle.
Substrate: caribsea moon sand
Filter: sunsun 304b (450gal/hr)
Two 150watt quartz heaters
Air pump and two air stones
Plastic decor (all from Petco)

Water
Constant 78f
pH 7.8
KH: medium
Hardness: hard
Ammonia: 0
Nitrite: 0
Nitrate: 10
Chlorine/ chloramine: 0
Test kits are all API

Weekly 25% water changes using Prime in 5 gallon bottle before adding new water to tank. Water is sourced through an outdoor tap and municipal water (Oceanside, CA).

I add seachem stability upon water change in response to repeat animal deaths.

So here's the short and curlies:

originally stocked with skirt tetras but all died with red gills and some had what looked like red eyes. Deaths occured within 2 weeks. Fish barley ate in this time.

Due to hard water and somewhat basic pH I tried my hand at small African cichlids (electric blue & yellow & acei and some other "assorted"). They were inteoduced 3 or 4 at a time to the tank.

Here's the repeat schedule:

Day one: fish acclimate (float bag, slowly exchange bag water for tank water over 45 minutes or so). Lights off.

Day two: fish establish their areas, eat, active, interactice with tank. Pwc 20% with treated (Prime) water that is same temp as tank.

Day three-five: fish will not eat a variety of foods. Some flash slightly. Others swim vertically with head pointed upward and tail pointed down. Some try to bury themselves in substrate as if they're holding on.

Day 6: most fish stay near bottom of tank but some stay very close to the surface. No fish are gasping at the surface.

Day 7: pwc of 25%

Day 8: all fish dead. Several would have died during days 3-5.

Since going through this process a couple times now I dosed the tank with API general cure with the last 3 fish in. Since dosing the fish have been huddled in one corner near the surface and are trying to hide their faces in the seal of the tank.

Any suggestions/ comments, advice and courses of action will be taken bery seriously. Thanks for your time.
 
Freshwater fish constantly dying!

Hi all. New to posting on this forum but have been following threads for quite some time. I've been keeing fish for some 20 years.

Parameters.
Tank
75gal. Cycled for 2 months fishless cycle.
Substrate: caribsea moon sand
Filter: sunsun 304b (450gal/hr)
Two 150watt quartz heaters
Air pump and two air stones
Plastic decor (all from Petco)

Water
Constant 78f
pH 7.8
KH: medium
Hardness: hard
Ammonia: 0
Nitrite: 0
Nitrate: 10
Chlorine/ chloramine: 0
Test kits are all API

Weekly 25% water changes using Prime in 5 gallon bottle before adding new water to tank. Water is sourced through an outdoor tap and municipal water (Oceanside, CA).

I add seachem stability upon water change in response to repeat animal deaths.

So here's the short and curlies:

originally stocked with skirt tetras but all died with red gills and some had what looked like red eyes. Deaths occured within 2 weeks. Fish barley ate in this time.

Due to hard water and somewhat basic pH I tried my hand at small African cichlids (electric blue & yellow & acei and some other "assorted"). They were inteoduced 3 or 4 at a time to the tank.

Here's the repeat schedule:

Day one: fish acclimate (float bag, slowly exchange bag water for tank water over 45 minutes or so). Lights off.

Day two: fish establish their areas, eat, active, interactice with tank. Pwc 20% with treated (Prime) water that is same temp as tank.

Day three-five: fish will not eat a variety of foods. Some flash slightly. Others swim vertically with head pointed upward and tail pointed down. Some try to bury themselves in substrate as if they're holding on.

Day 6: most fish stay near bottom of tank but some stay very close to the surface. No fish are gasping at the surface.

Day 7: pwc of 25%

Day 8: all fish dead. Several would have died during days 3-5.

Since going through this process a couple times now I dosed the tank with API general cure with the last 3 fish in. Since dosing the fish have been huddled in one corner near the surface and are trying to hide their faces in the seal of the tank.

Any suggestions/ comments, advice and courses of action will be taken bery seriously. Thanks for your time.

I guess I should add that there are no obvious symptoms of ich or velvet. The tank water has no noctious smells. No drastic spikes in water chemistry (testing daily at this point). I don't use cleaning chemicals near the tank. And whatever affects the fish kills ghost shrimp in about 3 days.
 
Did you test the water AFTER your fish had died? I'm wondering if tank hasn't been cycled and ammonia poisoning is killing them.
 
Did you test the water AFTER your fish had died? I'm wondering if tank hasn't been cycled and ammonia poisoning is killing them.

Thanks for responding, Munroco. I did test after each death. I have a liquid ammonia test and it shows zero every morning. The test seems to work as I used it during cycling to maintain my ammonia levels. The fish didn't exhibit the common symptoms of ammonia poisoning such as gasping at surface or red streaking.

Because I've become really sensitive about this tank, I'm using 15% more Prime at pwc's to really ensure that chlorine, chloramine and ammonia are in check.
 
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I'm leaning towards an ammonia spike. Don't know if you have any fish left but I would do 50% daily water changes w/ prime. I have a QT that I just cannot get cycled so when I buy new fish I put an old piece of filter from my main tank and do 50% water changes daily. So far this has worked. When i transfer the new fish I take it really slow (over a couple of hours) I may be overly cautious but I haven't lost 1 fish.

Another thought, have you tested the tap water? Maybe that's the problem?
 
I'm leaning towards an ammonia spike. Don't know if you have any fish left but I would do 50% daily water changes w/ prime. I have a QT that I just cannot get cycled so when I buy new fish I put an old piece of filter from my main tank and do 50% water changes daily. So far this has worked. When i transfer the new fish I take it really slow (over a couple of hours) I may be overly cautious but I haven't lost 1 fish.

Another thought, have you tested the tap water? Maybe that's the problem?


Thanks crystal. I did test the tap water. It sits at 7.8ph, hard, < 5 ppm nitrate, no nitritie or ammonia and chlorine seems pretty standard.

I think my cycle must be very sensitive. So much so that I must not be able to add nore than one fish per week. I will seek out some media from an established filter. Perhaps that will help to support my flora.

I have one fish left who is no longer listless, is mildly active and he tries to eat. I do need to do some water changes today as the nitrates are close to 20 ppm right now.

I've ordered some life plants and will leave them in the tank for a couple weeks to see what changes they can make. Pehaps that will be my problem solved. Thanks again for your courteous response.
 
I do not normally respond in disease threads because of my lack of experience with such issues (in the hobby over 25 years now) but a couple things seem likely to me here.

First, I would doubt the tank is not cycled; adding one fish will absolutely never cause any sort of mini-cycle or problems related to ammonia/nitrite/nitrate unless they are already there and showing up in tests. Which brings me to the Prime and Stability and API General Cure.

Prime should never be dosed beyond the amount required to detoxify chlorine/chloramine, and only for the volume of fresh water being added. I know Seachem say using more will not harm fish, but this is not true; any substance added to the water gets inside fish by osmosis through the cells and gills, and in the bloodstream and internal organs. Such substances should bee kept to the absolute minimum. It should be obvious that any chemicals entering the bloodstream will have consequences for fish as any animal. I'm not saying this killed the fish, it didn't (unless the dose was way over, when it certainly could) but it adds to the problem and at the very least causes stress which weakens fish.

Stability should not harm, but there is also no need to be adding it. The less stuff in the water, the better for reasons other than the one above.

As for these "general cures," forget them. They rarely do anything beneficial, often thee opposite, as here again this stuff is in the water and inside the fish and that in itself is detrimental no matter the consequences. Also, these general cures are ineffective for most issues. Like taking aspirin to cure cancer, it won't, but it may do more harm.

The tests show nothing amiss, so assuming they are accurate, the likely options are either some toxin in the water or an internal disease such as a pathogen or protozoan. I have twice battled internal protozoan that killed the fish with no external signs of any sort until death.

Toxins in the water can come from something accidentally or deliberately added to the tank water, or from the piping. Copper pipes are common, but they do leach copper and if new can be fatal to fish. Are you using a water softener? Any rock or wood in the tank--these can contain deadly toxins undetectable that slowly leech out; I had this years ago from a large chunk of wood purchased in a fish store.

Internal protozoan need a microbiologist examination of dead fish to identify. I was advised to use metronidazole added to the food, and both times it worked. Too late now with all fish dead, though you could try it if the one is still alive. Seachem make a product called MetroPlex that can be added to the water or mixed with food; the latter (in the food) is far more effective. It takes a few days to deal with the protozoan, but I saved half of my display tank's fish twice using this treatment. I learned the importance of quarantining new fish for several weeks.

With all fish removed, protozoan will not likely remain in thee aquarium after a time, though not knowing all of them or their life history I can't say for certain. Toxins leeched from something can remain without fish.

Byron.
 
I do not normally respond in disease threads because of my lack of experience with such issues (in the hobby over 25 years now) but a couple things seem likely to me here.

First, I would doubt the tank is not cycled; adding one fish will absolutely never cause any sort of mini-cycle or problems related to ammonia/nitrite/nitrate unless they are already there and showing up in tests. Which brings me to the Prime and Stability and API General Cure.

Prime should never be dosed beyond the amount required to detoxify chlorine/chloramine, and only for the volume of fresh water being added. I know Seachem say using more will not harm fish, but this is not true; any substance added to the water gets inside fish by osmosis through the cells and gills, and in the bloodstream and internal organs. Such substances should bee kept to the absolute minimum. It should be obvious that any chemicals entering the bloodstream will have consequences for fish as any animal. I'm not saying this killed the fish, it didn't (unless the dose was way over, when it certainly could) but it adds to the problem and at the very least causes stress which weakens fish.

Stability should not harm, but there is also no need to be adding it. The less stuff in the water, the better for reasons other than the one above.

As for these "general cures," forget them. They rarely do anything beneficial, often thee opposite, as here again this stuff is in the water and inside the fish and that in itself is detrimental no matter the consequences. Also, these general cures are ineffective for most issues. Like taking aspirin to cure cancer, it won't, but it may do more harm.

The tests show nothing amiss, so assuming they are accurate, the likely options are either some toxin in the water or an internal disease such as a pathogen or protozoan. I have twice battled internal protozoan that killed the fish with no external signs of any sort until death.

Toxins in the water can come from something accidentally or deliberately added to the tank water, or from the piping. Copper pipes are common, but they do leach copper and if new can be fatal to fish. Are you using a water softener? Any rock or wood in the tank--these can contain deadly toxins undetectable that slowly leech out; I had this years ago from a large chunk of wood purchased in a fish store.

Internal protozoan need a microbiologist examination of dead fish to identify. I was advised to use metronidazole added to the food, and both times it worked. Too late now with all fish dead, though you could try it if the one is still alive. Seachem make a product called MetroPlex that can be added to the water or mixed with food; the latter (in the food) is far more effective. It takes a few days to deal with the protozoan, but I saved half of my display tank's fish twice using this treatment. I learned the importance of quarantining new fish for several weeks.

With all fish removed, protozoan will not likely remain in thee aquarium after a time, though not knowing all of them or their life history I can't say for certain. Toxins leeched from something can remain without fish.

Byron.


Thanks so much, Byron.

I too have had bad experiences with wood and rocks...even those from an aquarium store. I have since been trying to eliminate contaminants and as such, have removed all rocks from the tank.

And you're right about the general cure, I've never had to use anything like that and it wasn't confirmed that the fish had parasites. They just ticked a lot of the boxes on the symptoms.

I plan to let the tank cycle for another month without fish in the hopes that the tank can recover and the cycle can become better established.

Thanks again.
 

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