Fish Dying Unknown Reason

[Emily_R]

Hi all,

I have a 55g aquarium that’s been active for around 4 months. Throughout that time I’ve added 2 angelfish, a betta, 6 mollies, 3 platys, 4 neon tetras, and about a dozen feeder guppies. Between last night and this afternoon 5 of my mollies died and all but 2 of the feeder guppies. My platys are all sitting at the bottom of the tank and look dead until you disturb the water (i thought they were dead so i was going to net them out). The betta is not his usual self and the angels seem fine. I ran a water test today and all of my levels are normal, about a week and a half ago i did a 50% water change, and i haven’t added any new fish within the past month. My water is a little cloudy but not to the point where i’d find it concerning. What could be causing all of my fish to get sick/die?

 

[Byron]

Welcome to TFF.

First thing is to list your test results/water parameters whenever you post about an issue/problem. "Normal" is subjective and other members can have no idea what this might mean, and when diagnosing an issue the exact test results and parameters can be key. Parameters includes GH, KH, pH and temperature. Test results for ammonia, nitrite and nitrate (whichever you have).

Second thing is to always let us know about any and all additives (water conditioner, plant fertilizer, anything else). And of course water change schedule which you do mention but is this regular or just because of something? It is advisable to change somewhere between 50-70% every week regardless, and more often if there are problems like here. It is amazing the benefit of a water change, though I am not suggesting it will cure everything, but it certainly helps.

A rapid death of several fish literally overnight suggest something in the water, or something wrong with the chemistry. Did the dead fish show any abnormal behaviour recently? Things like lethargy, increased rate of respiration, clamped fins, flashing (rubbing on objects)?

Water parameters, especially GH (general or total hardness of your source water) is particularly crucial as you have fish that must have hardish water (mollies especially, platy also) and fish that "prefer" softish water though they are somewhat tolerant depending upon the GH. But at the same time, another issue could be ammonia, as mollies are very intolerant of any ammonia.

 

[Emily_R]

I have a liquid test kit for PH, Nitrite, Nitrate, and Ammonia. PH is around 7, Ammonia is 0, Nitrite is 0, and Nitrate is 0 (this has always tested 0 but I have never had any ammonia/nitrite spikes aside from during the initial setup of the tank). 2 days ago I added a dose of algaefix because my water was cloudier than it is now. I usually do between 50-60% water changes every other week. I changed my filter cartridges as well if that is helpful input, but that was in the beginning of November.

I do not know anything about the hardness of the water I use so I apologize for the lack of that information (but I haven’t had any problems like this prior and I haven’t changed water sources). What would I do to test that, are there test kits for water hardness like there are for the PH, Ammonia, etc.?

When the tank was first set up I added API brand Root Tabs but haven’t added anything like that since and I haven’t used any water conditioners before.

As for the dead fish, they all seemed normal within the past few days. No one was lethargic, acting unusual or anything like that and everyone was eating fine.

If there’s anything I should add to the water (after a water change which I’ll do tonight) please let me know, I’m making a trip to petsmart to get my water tested there for a second set of results and would be able to pick up anything I needed.

Thanks!

 

[Byron]

I see a couple things now. First, you say you never use water conditioner...do you not treat the tap water for chlorine/chloramine? Or are you on a private well with no chlorine added? This is crucial...if you do have chlorine or chloramine in the tap water, you must use a conditioner. I use and highly recommend API's Tap Water Conditioner. It contains no unnecessary substances beyond the dechlorinator.

Ammonia, nitrite and nitrate is fine (the zero nitrate is not an issue as I assume you have live plants). No need to detail this as it is not the problem.

GH (general or total hardness) you must find out, check the website of your water authority (again unless you are using private well water). Or call them. There are tests but once you know the GH for the source water you won't need to test it much if at all, so see if you can pin this down. Or take a sample of tap water to PetSmart and ask them to test; but make sure you get the number and their unit of measurement so we can be certain. Vague terms like "moderate" or "hard" mean nothing without the number.

The new filter cartridge in November is not likely to be causing issues now, and with zero ammonia/nitrite this is not an issue anyway. I could say more about rinsing rather than changing filter media, but I would need to know the filter and this is not the issue so we can leave it.

Now to what I suspect may be the actual issue...algaefix. Never use these products; anything that can or is supposed to kill something in the tank is without question going to harm fish, guaranteed. They may die, or live through it, but they are still harmed or affected negatively. This is because every substance we add to the water gets inside the fish, naturally. It enters the bloodstream and internal organs, and at best will weaken the fish making them more susceptible to other issues, but often it is far worse, even causing death. Different fish have different sensitivities to various chemicals, but they are all detrimental regardless of what the manufacturer may say. I would do an immediate large water change, 75% of the tank volume...but you need to condition the water if you have chlorine or chloramine or this alone will kill the fish.

 

[Emily_R]

I am on well water where I live, so I’ll take a sample of that with me when I go to Petsmart and I’ll pick up a water conditioner while I’m there.

I do have live plants, so thanks for mentioning that, but how does that affect the Nitrate levels? Just curious.

I did not realize the Algaefix would harm the fish, it says right on the bottle that it wouldn’t. What would be a better alternative to clear up the water when it starts getting cloudy/green? Water changes more often?

Again, thanks for all of the help! I appreciate it.

 

[Byron]

I am on well water where I live, so I’ll take a sample of that with me when I go to Petsmart and I’ll pick up a water conditioner while I’m there.

I do have live plants, so thanks for mentioning that, but how does that affect the Nitrate levels? Just curious.

I did not realize the Algaefix would harm the fish, it says right on the bottle that it wouldn’t. What would be a better alternative to clear up the water when it starts getting cloudy/green? Water changes more often?

Again, thanks for all of the help! I appreciate it.

You're welcome. Re the conditioner, this is not needed when you do not have chlorine or chloramine being added, so you can forget that. Though we do need to know the GH as there can sometimes be high mineral content in well water, but the conditioner is not likely to have much if any effect on this (it does detoxify heavy metals).

Cloudy water can be do to a couple of things. If it is greenish in hue, that is likely "green water" which is due to unicellular algae. Not harmful to fish on its own, so allowing it to clear naturally and keeping it from returning is the aim (I'll come back to this). If the cloudiness is whitish, yellowish or just "foggy" it is probably a bacterial bloom, diatom bloom, or organic bloom. Again, on their own not harmful to fish, so again we find the source and deal with that so it goes away and doesn't come back. Can be easier said than done, I know from experience with one tank.

The cloudy water is organic in origin. You said nitrate was zero, so I assume there is no nitrate in the well water (agricultural runoff can sometimes raise nitrate in well water, presumably not yours fortunately). So the organics are primarily occurring within the aquarium (normal) and this is determined by the fish load, and how much they are fed. Water changes obviously reduce organics, and vacuum of the substrate during removes more. Also keeping the filter media rinsed removes organics. Organics feed the bacteria or algae causing the "bloom," and light contributes. Strong overhead tank lighting can contribute to green water especially. Floating plants are good for this. Along with minimal feeding of fish (once a day, missing one or two days each week is fine).

I'll respond on the plants/nitrate issue in another post to follow.

 

[Byron]

Plants need nitrogen which is a macro nutrient. Aquatic plants are different from terrestrial which prefer nitrate. Most aquatic plant species prefer ammonium (ammonia) as their source of nitrogen. Plants readily take up ammonia/ammonium and will only turn to nitrate when the ammonium is insufficient in balance with everything else they need including light to drive photosynthesis. Fast growing plants take up more, and floating plants being the fastest growing are often called "ammonia sinks" because of the amount of ammonia/ammonium they can assimilate. [Another reason floating plants are beneficial.]

To very briefly explain ammonia/ammonium. This is a matter of positive and negative charged ions. The more acidic the water is, pH below 7.0, the more ammonium, and the more basic, pH above 7, the more ammonia. Ammonia is toxic to fish, plants and some bacteria; plants and some bacteria use ammonia so the toxicity depends upon the level. Ammonium is basically harmless.

Because plants take up ammonia/ammonium, and because they can do this faster than the nitrifying bacteria, and because nitrite is not produced as a result like it is with bacteria, there is less nitrite being created, and in turn less nitrate. So a low nitrate level in a planted tank is not due as much to the plants using nitrate as it is to the plants using more ammonia so less nitrate is resulting than would be the case with no plants.

Aquatic plants that prefer ammonia will only turn to nitrite and then nitrate if they need to. This is because the plant must use energy to change the nitrite/nitrate back into ammonium, and plants are intelligent enough not to do this unless they have no option. Note I said nitrite, then nitrate; there are studies suggesting that plants will take up nitrite before nitrate, but there has not been as much study of this. I certainly would not count on plants to deal with a nitrite problem, as the fish would probably be dead first.

So, in tanks with live plants that are relatively fast growing, nitrate is usually low. My tanks are fairly heavily planted, all have thick floating plant cover, and I stock some of them fairly heavily with fish. Nitrate remains in the zero to 5 ppm range, and has for over a decade. This is ideal, because we know that nitrates do poison fish, depending upon the level, fish species, and exposure time, so the lower the nitrate the better; nitrates at or above 20 ppm will significantly weaken many fish and kill some outright.

 

[FishGuest5123]

When you changed your filter cartridges in November, did you leave the old ones in for a while? If not, you likely lost your cycle. That would mean your fish have been living with toxins in the water for the last 6 weeks. Never put new cartridges in without leaving the old ones in also for a few weeks. You could very well have the 0 nitrates due to an uncycled tank. However, after 6 weeks I would think ammonia and nitrites would have processed and nitrates be showing. The plants could be helping but I question how steady the cycle is.

 

[Emily_R]

I did leave an old cartridge in the tank for 2 weeks after putting new ones in.

I just got back from petsmart, everything showed up the same on their test as mine except theirs says my PH is low, and the person I talked to did not seem at all bothered by the fact that I used Algaefix. So i’m not sure what to go by as far as those two things, but I’m going to do a water change and add PHup and monitor what happens. While I was there I also got a stress coat and bought test strips so i have two test sources.

 

[Colin_T]

If your fish suddenly die over night and the water tests for ammonia, nitrite, nitrate & pH are good, then the problem is either a disease or poisoning, usually poisoning.

In future, if you ever lose a fish or it looks unwell, test the water and do a 75% water change and gravel clean the substrate immediately. Then do a 75% water change and gravel clean each day until the issue is identified or resolved. The big water changes will dilute harmful substances in the water and reduce disease organisms and buy you some time to try and figure out what is going on.

I would guess the issue was either an overdose of the algaefix or you contaminated the water with something on your skin (perfume, anti-bacterial wipe or soap residue, or anything else that is harmful to aquatic organisms).

Pictures of the sick, dead fish also help with identifying issues.

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If your tank water is going green, either reduce the light or increase the number of live plants in the tank.

Try not to use chemicals to control algae because it can easily be controlled by reducing light or adding plants to use the excess light.

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If you are using well water, you do not need a water conditioner/ dechlorinator. However, you should check the well water every month to make sure it is free of ammonia, nitrite, nitrate and the pH is in a safe range for the fish you keep.

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There is more information about what to do if your fish get sick at the following link. It is pretty long and boring but worth reading when you have a free moment. I recommend printing it out and reading it in bed to help fall asleep.
http://www.fishforums.net/threads/what-to-do-if-your-fish-gets-sick.450268/

 

[Emily_R]

I did a water change last night and I’ve added some PHup and everyone is looking more lively tonight. Keeping my fingers crossed that things keep looking up! Thanks to all that gave suggestions and offered their knowledge.

After the holidays I’ll plan to add some more live plants. Any specifics that would be good to add? Right now I have three Amazon Swords, three Gold Ribbons, an Anubias, and a moss ball.

 

[Colin_T]

Do you have a light on the tank?
If yes, what type?
How many watts?
How long is the light on for each day?

Good plants to try include Ambulia, Hygrophila polysperma & rubra/ ruba, narrow Vallis, Water Sprite (Ceratoprteris thalictroides/ cornuta).

The water sprite is a floating plant but can also be grown in the substrate. The other plants should be planted in the substrate.

 

[FishGuest5123]

Fingers crossed for your fin babies.

 

[Byron]

I did a water change last night and I’ve added some PHup and everyone is looking more lively tonight. Keeping my fingers crossed that things keep looking up! Thanks to all that gave suggestions and offered their knowledge.

After the holidays I’ll plan to add some more live plants. Any specifics that would be good to add? Right now I have three Amazon Swords, three Gold Ribbons, an Anubias, and a moss ball.

Do NOT use pH adjusting chemicals. These can harm fish. Plus they usually do not work long-term, I will explain this.

Fish in an aquarium produce organics and these as they decompose create carbonic acid which lowers pH. This is normal, and not generally a problem. Regular substantial water changes, not over crowding, not overfeeding all aid in a stable water chemistry.

The effect of the CO2/carbonic acid on the pH is regulated by the GH and KH of the water. Do you know these numbers (for the source tap water is fine)?

The water chemistry will settle on its own, depending upon thee above. It is best to leave this alone, and select fish suited. The "low" pH, exactly what is it? It may be fine. And what fish do you have?

The pH chemicals usually work immediately to raise/lower (depending which you use) the pH, but over 24-48 hours the natural water chemistry works top bring the pH back to where it should be in those conditions. Fluctuating pH is very hard on fish.

Generally speaking, the answer to any issue/problem/situation is NOT using additives. These do affect fish and weaken them, no matter what any store tells you. Remember, the store unlike those of us on this forum want to sell products to make money.

 

[FishGuest5123]

I didn’t want to stir the pot but I agree with Byron. PH adjusting chemicals usually do more harm than good and fast PH changes can kill your fish.