Fish dying over several days

I wish I had found this site earlier, but am hoping someone may be able to help me understand what is going on with my tank at this point.
I have been starting up a new tank with African Cichlids (Lake Malawi, many mbunas) in my 75gal tank. The temp is kept at a constant 79 degrees, and I use Seachem Cichlid Lake Salt and water conditioner when adding new water. I was told by the LFS to use Seachem Stability to help cycle the tank prior to adding fish. I followed the instructions exactly, and added the fish a week later (while continuing to use Prime) and needless to say it didn’t work as well as hoped. I got the Ammonia spike and did water changes and put Ammo chips in the filter to bring the levels down and the fish were fine. I however got a huge spike in Nitrites, much larger than I ever had with the Ammonia, and immediately began daily water changes and using additional dosages of NovAqua+ and AmQuel+ (at levels indicated as safe on the bottles) to help rid the tank of the toxins and hopefully minimize the damage.
It was about a week following this that I began having fish die, one at a time, over multiple days. I was thinking initially that this was only due to an unfortunate side effect of the nitrite levels, but days would pass without any issues and then another fish would die. I switched to Seachem Prime to condition the water, and was able to finally secure some material from an established tank that I knew was disease-free to help seed the tank with bacteria. At this point the Ammonia and Nitrite levels have dropped off to 0 and the Nitrates have kicked in for about 1.5weeks. With the rise in Nitrates, and the beneficial bacteria, the tank had gotten quite cloudy and I used Seachem Clarity, which worked well, hoping to improve the water quality as best I could to not stress the remaining fish. I did an extra clean of the filters, in tank water, the next day to clean out the extra gunk as well. I have been obsessively testing the water daily, and doing the weekly water changes as normal now that the levels have evened out. I have however still had 2 deaths since the Nitrites were brought down to 0 and I am wondering if there is anything else that I could be missing. I don’t want to lose any more fish and I feel like I have done everything I can think of. I come home each day in dread of finding another casualty but I really can’t think of anything else I can do, and just hope that the tank has finally stabilized. Any help or comments would be greatly appreciated!!!

How long did you wait to put fish in the tank after you set it up?

Did you check the pH drastic spikes and drops can cause fish to stress and die also.

Did the fish look sick scratching themselves on decorations, bad coloring, heavy gill movement ect. Sometimes one is sick the rest follow.

Do you have any fish bullying the rest to death?

Was this a new or a used tank? If used was soap ever applied to it, or cleaning chemicals?

How many fish did you add? And what size?

Sometimes it takes a few days for fish to sucumb to a massive chemical spike. Unfortunatley it could be the residual effect of Ammonia jumping up the Nitrites right behind it.

Hope this helps a bit.
Sorry for your loss

I added the fish a week after running the tank with SeaChem Cycle as this was supposedly safe per the instructions and I had been given good reviews of the product.
The tank was more or less new, it had been used in the past but not anytime recently, and it was cleaned out with diluted bleach and rinsed thoroughly until no residue remained. I dont think this would be the issue though since the fish were fine for the first few weeks in the tank, and the Nitrite spike occurred prior to the first fish dying.
I had tested the pH, but not as often as the Ammonia and Nitrite, but I have multiple Texas Holey Rock in the aquarium as well that are supposed to help maintain high pH, and the city tap here runs around 8.0-8.2 which is ideal for the cichlids.
I had seen some of the fish scratching on the sand substrate occasionally and heavy gill movement, but I assumed this was a reaction to the Ammonia and then Nitrite spike which I was trying to control.
I am more concerned now with trying to prevent more from dying, though the remaining fish appear to be ok, but any of the fish that died did so quickly without prolonged behavior issues that I was able to recognize. Essentially I will check the fish in the morning and evening and everything will look fine, but during the day while at work or at night is when they crash and I will return to find one dead.
I was thinking this was just the residual effect of the stress caused by the tank cycling unfortunately, but I wanted to make sure so I didnt miss anything that I could be doing to help keep this from continuing to happen.

Sounds to me like the effects of a fishy cycle. When you're doing fishy cycles it is very important to do water changes almost daily instead of once a week. Once the tank completes the cycle, then you can get into a normal maintenance routine with water changes.

It is damage for them being in the tank cycle. Theirs not much you can do.


Oh one thing you are using too many chemicals, prime and the cichlid lake salt are all that you should be using. That cloudiness was a good bacterial bloom and not harmful to the fish in any way. You need to cut back on the chemicals and let the tank run its course. The more you try to chemically fix things that are not issues the more stress you put on the fish.

How many fish did you add at once?

That bacteria in a bottle is pretty much a waste of money as you have found out.

I'm glad you found us! We are more than happy to help answer any and all questions you may have

Caroline wrote:

I added the fish a week after running the tank with SeaChem Cycle as this was supposedly safe per the instructions and I had been given good reviews of the product.
The tank was more or less new, it had been used in the past but not anytime recently, and it was cleaned out with diluted bleach and rinsed thoroughly until no residue remained. I dont think this would be the issue though since the fish were fine for the first few weeks in the tank, and the Nitrite spike occurred prior to the first fish dying.
I had tested the pH, but not as often as the Ammonia and Nitrite, but I have multiple Texas Holey Rock in the aquarium as well that are supposed to help maintain high pH, and the city tap here runs around 8.0-8.2 which is ideal for the cichlids.
I had seen some of the fish scratching on the sand substrate occasionally and heavy gill movement, but I assumed this was a reaction to the Ammonia and then Nitrite spike which I was trying to control.
I am more concerned now with trying to prevent more from dying, though the remaining fish appear to be ok, but any of the fish that died did so quickly without prolonged behavior issues that I was able to recognize. Essentially I will check the fish in the morning and evening and everything will look fine, but during the day while at work or at night is when they crash and I will return to find one dead.
I was thinking this was just the residual effect of the stress caused by the tank cycling unfortunately, but I wanted to make sure so I didnt miss anything that I could be doing to help keep this from continuing to happen.

If your tank was only running a week there is no way that your water was safe. Not enough good bacteria in the water to keep levels safe after only a week.

If this is your only tank you might have to wait a little longer then the normal aquatics guru. Most of us have multiple tanks and use other sources to get our good bacteria. Like filters that have been used on another established tank, sand, rock, gravel or something that had good bacteria on it. Heck sometimes to start a new tank I will do a water change on a established one and use theat water to start the new tank.

I do not put ANYTHING in the water besides prime to kill the chlorine. Let nature and all that do its own thing.

Fern wrote:

You need to cut back on the chemicals and let the tank run its course. The more you try to chemically fix things that are not issues the more stress you put on the fish.

Agreed 10000%

Sometimes I hear people getting stressed out about there water levels. I have never checked mine and I am running 30 tanks. I use to have 40. Not saying this is the way to go but I know what I know and prime and tap water is all you need. Don't let the fish store down the street tell you diffrent the only thing they want is you to spend more money.

If you want to test out your fish stores knowlege go in and ask some questions.

What Mbuna do you have?
If they have frontosa...ask them what the collection point is.
Ask them if they have spoonge filters.
Ask them if cichlids are egg layers or mouth brooders.
If they dont know the answers I would not shop there.

lol ya def true, i normally dont test my water unless a waterchange for my discus so i dont put in anything that may stress them out and wen i have deaths or sickness. but other than that if your fish is acting normal healthy and all then i dont, they tell me if their sick or something is wrong with the water.

You do need to test weekly till your tank is fully cycled. Don't add any more fish till everyone is doing well and your tank is stable.

But I agree once your tank is stable you will only need to test when the fish look 'off' that's the way I do it. Or a PH test when moving a few fish from one tank to the other, that just tells me how long I need to spend acclimating them.


Just hang in there and we will help you out! Once you get the basics down fish keeping is a very very fun thing!!!

Thanks everyone for your help, and it seems like my suspicions that this was fall out from the effects of the tank cycling were correct. Though I wish there was something I could do to ensure the rest of the fish make it, I feel terrible that they were put through this. It makes me so angry that I was talked into believing that the Cycle product would work, and I followed the directions to the letter. Its kind of strange because the rest of the Seachem products seem great but what can you do. I guess its just a waiting game at this point. Is it safe to assume that the tank is cycled now that I am getting the increase in Nitrates and the Ammonia and Nitrite are 0 or can there be another spike for some reason? I don't want to be caught off guard, and continue to test the water every day out of fear of that. Thanks again

Thanks everyone for your help, and it seems like my suspicions that this was fall out from the effects of the tank cycling were correct. Though I wish there was something I could do to ensure the rest of the fish make it, I feel terrible that they were put through this. It makes me so angry that I was talked into believing that the Cycle product would work, and I followed the directions to the letter. Its kind of strange because the rest of the Seachem products seem great but what can you do. I guess its just a waiting game at this point. Is it safe to assume that the tank is cycled now that I am getting the increase in Nitrates and the Ammonia and Nitrite are 0 or can there be another spike for some reason? I don't want to be caught off guard, and continue to test the water every day out of fear of that. Thanks again

ps dont be affraid to sign up and become a member!

Test weekly and do weekly water changes that's the best thing you can do for them now is keep the water good and clean.