What just killed all my fish?!

[Byron]

The issue here is absolutely nothing to do with cycling; after 2 months, the tank would likely be cycled. The cause is in post #3--the actions mentioned respecting the pH is clearly the problem.

First, guppies need moderately hard water with a basic pH (above 7.0). The GH is key. We need to know the GH of your source water. But the fact that the pH drops so fast below 7 suggests the GH is likely on the soft side. And that is your problem. We can go into this more when the GH is known. And what is the pH of the source water? Remember to outgas the CO2 when testing tap water for pH (not needed for tank water) by letting a glass of tap water sit 24 hours, then test pH.

Second point...never, absolutely never use pH adjusters with fish in the tank. The rapid change in pH due to this chemical concoction killed the fish. The excess mucus is proof of that. Water issues will cause this, here it is the (presumably) low GH, and the sudden substantial pH rise. GH, KH and pH are closely connected, and you cannot safely adjust pH without dealing with the GH and KH.

Ironically, the guppies were managing in the soft acidic water (though for how long is questionable, as this slowly weakens them and they would have died eventually). Now you know. And you have learned the hard way like many of us also did. GH is crucial to fish health. And pH follows the GH and should be left alone.

 

[GuppyMama1234]

My nearest quality shop is just over an hour away. Fortunately, I have a quality set of test kits, so I'm not dependent on others to tell me what state my water's in.

We use API master test kit but ofcourse that only covers PH, ammonia, nitrite and nitrate. What do you use for GH and KH? I’m at the fish store now trying to find a good test kit for that. Other than the things I just mentioned is there anything else I need to be testing for? I’m on a well system and have spring water. It’s soft water and the ph is o oh 6.4 and I have no idea what to do about that

 

[Fishmanic]

You need to stock fish that will thrive at your ph and gh. Dont try to alter your water parameters… it’s best to get fish that are suitable in your water type

 

[Byron]

We use API master test kit but ofcourse that only covers PH, ammonia, nitrite and nitrate. What do you use for GH and KH? I’m at the fish store now trying to find a good test kit for that. Other than the things I just mentioned is there anything else I need to be testing for? I’m on a well system and have spring water. It’s soft water and the ph is o oh 6.4 and I have no idea what to do about that

Since this is private well water, you can either buy a GH/KH test or take some water in to the store and ask them to test the GH and KH. If you buy a test, the API GH/KH test is good, I have used it. Once you know the GH and KH of the well water, and assuming you do not attempt adjusting it, you're set. And I really would not try adjusting it, this is fraught with issues.

Another issue comes in here...do you have any sort of water softener hooked up for your well water? Or is it just piped in and used "as is?" This makes a difference too, as most water softeners are hazardous to fish.

 

[Bruce Leyland-Jones]

We use API master test kit but ofcourse that only covers PH, ammonia, nitrite and nitrate. What do you use for GH and KH? I’m at the fish store now trying to find a good test kit for that. Other than the things I just mentioned is there anything else I need to be testing for? I’m on a well system and have spring water. It’s soft water and the ph is o oh 6.4 and I have no idea what to do about that

API do a decent enough Hardness testing kit, testing for General Hardness (GH) and Carbonate Hardness (KH*).
One of my local fish stores has a water source with a relatively low pH, apparently running at 6.2 at the moment. They showed me that they run their water over oyster shells and raise it to 6.9.
Choosing fish to match your water is certainly the simplest way of doing things. If you alter your water, you're going to have to keep on altering it with almost every water change. That said, there are many fish that will thrive in a wide range of water parameters, especially those that aren't wild-caught.

*I guess someone had a less-than adequate schooling.

 

[Spyro]

View attachment 141592Does anyone Know what is going on here... these fish were perfectly fine two days ago and within the last 24 hours almost every fish in the tank died and looks like this! Please help!!

It sounds like wild PH fluctuations killed your fish.
You might have Oxygen/Co2 balance issues or are you dosing with something that affects PH (other than PH booster you mentioned) Fertilizers?

Is your tank heavily planted? Do you have strong enough oxygenation? Are you dosing with Co2 or liquid Co2 of some sort?

But first thing I would look into is your KH reading. (if you don't have Co2 dozing)
If your tap water lacks KH = your PH will fluctuate wildly and kill your fish.
You might need to fix your KH level.

 

[FishHobby99]

We had no idea what a biological cycle was. Both of us (my husband and I) have had fish tanks before and had never even heard of it. Growing up, my parents bred guppies and mollies and never had a fish die, save for old age and they never added anything to the water nor did they use a test kit or do weekly water changes. We just did what the guy at Pet Smart said (which is unfortunate and has caused great loss). He said to add the bacteria and a couple goldfish and wait a week before adding anything else we didn’t learn the proper way to do a true cycle until after all this other stuff had happened. Now we are starting completely over and doing it the RIGHT way. I was just hoping someone would know what the white scummy crap was so I would know if I needed to throw out the rocks and quarantine the live plants... just need to know what to do from here. All my fish in that tank died ( I have 3 other tanks set up with no problems) and I would like to know what this white funk is.

I am so sorry. What kind of fish do you have? Or had there? How big is the tank.

 

[Fish culturist1990]

Hi
First, guppies are usually hardy species and they do well in normal quality waters. They are not very sensitive for water quality changes unlike some other species. So maintaining a guppy tank is not that difficult.
But since all of them died, there should be a sudden and major change in water quality. Before you add fish next time follow these tips:
1. Do a thorough cleaning of the whole tank (including aquarium gravel, ornaments, plastic plants etc). Clean everything.
2. If you've live plants, better to keep them separately for some time to check for any unwanted organisms (such as snails, snail eggs etc). If you see any such organisms better to treat the plants with mild concentration of potassium permanganate. But thoroughly wash those plants in clean water before you add them into a tank with fish. Because that chemical is toxic for fish!
3. Better not to add unwanted chemicals to regulate pH, ammonia etc. If you maintain the tank properly then water quality will be fine and there won't be much trouble
4. I have no idea about the whitish stuff on the body of the guppies. But anyway since they're already dead we can't save them.
5. Depending on the size of your tank better to do partial water changes (maybe 50%) once every two weeks. Also clean the filters etc. This will allow you to avoid any unwanted troubles.
6. Check your water source. If it contains any cleaning chemicals such as chlorine then you must get rid of them before adding your fish.

Better luck next time with your new set of fish!

 

[Perbud]

This is definitely a ph problem..
To increase the ph from a very toxic level below 6.0 you must add about a quarter of a teaspoon of baking powder-known as sodium bicarbonate(liquid ph up is useless)immediately…
See where the ph level is in 24 hours and increase it only again with a little less than a quarter of a teaspoon if it is not yet at 7.0 .Do not over do it on the dosage since wide fluctuations of ph(and temperature) can kill your fish. Guppies and all livebearers do best in ph 7.0-7.5..but can all thrive in 7.0.You shouldn’t increase ph by more than .1 each day.

 

[dasaltemelosguy]

View attachment 141592Does anyone Know what is going on here... these fish were perfectly fine two days ago and within the last 24 hours almost every fish in the tank died and looks like this! Please help!!

I'm so sorry to hear about your loss. What happened is two-fold: Firstly, the PH-Up killed your fish. the reason being, fish need days to adjust to even small PH changes and a large one that occurs abruptly, causes internal organs to rupture known as Osmotic Shock. Fish DO tolerate PH changes but VERY SLOWLY. No more than 0.3 change per day. I've seen a 0.5 change kill an adult parrot fish that was otherwise healthy.

Your PH collapsed because your tank is not cycled. A fully cycled tank would not become acidic under such a small bioload. The bottled bacteria at best, speeds up the cycling process but it still take 2-3 weeks to be fish-ready. One of my tanks has a very high bioload requiring two large canister filters. We lost power for a few hours and the fish looked unusually uncomfortable. The PH had already fallen in just hours.

The guy at the LFS unfortunately gave you very bad advice.

Since you still have neon's, you'll have to cycle the tank with the fish in it. That's normally not a good idea as it can kill the fish but from your numbers, you're already on the way.

IMO, I'd first change 50% of the water. Obviously remove anything dead and vacuum he gravel. Clean the filter but NOT the biomedia. Add more bottled bacteria and keep ONLY the neon's until you read 0 ammonia and 0 nitrite, especially the nitrites as 0 nitrite is a direct indicator that the tank is cycled.

Once you reach that point, my guess being, 2 weeks possibly 3, add a few more fish and do the same. SLOWLY is the key. There's an enormous and erroneous emphasis placed upon 'correct PH' but most fish will adjust to most any PH if given enough time. I'd never adjust the PH unless breeding were an issue.

Lastly you can add crushed coral to the gravel or in the filter. It adds good minerals and it begins to dissolve at PH=7.4 such that should you get a PH crash, it holds it up around 7.4 by dissolving alkaline calcium compounds into the acidic water, raising the PH.

The white stuff is fungus. That type of fungus grows rapidly if the PH drops to 6 or below.

Again, I'm so sorry to hear what happened. It'll work out so long as you take weeks between major changes and additions.

 

[Lajos_Detari]

I didnt read all the posts here.
Other than pH swings, take note that Columnaris bacteria can kill fish very fast.

Guppies are one of the fish that are prone to Columnaris.
Did the fish have any white patches and breathing fast before they died? These are the symptoms of Columnaris.

Here are some info about Columnaris:

https://www.myaquariumclub.com/columnaris-and-what-i-have-learned-about-the-types-causes-and-treatments-1689.html

One moment, please...

 

[Mary~ECole]

View attachment 141592Does anyone Know what is going on here... these fish were perfectly fine two days ago and within the last 24 hours almost every fish in the tank died and looks like this! Please help!!

It looks like a fungus took over the tank which would have been introduced by any new fish you put in. Here’s what you do
First take out any living fish and put them in a small fish bowl with an air stone and put in the correct amount of tetra all in one treatment you can get it at Walmart.
next take out everything in the tank including substrate. Wash the inside with white vinegar and water or bleach and water and rinse well.
clean any decorations from the tank in the same fashion .
You’ll want to buy all new substrate. Basically you’ll have to start your tank over again. While your tank is being recycled you’ll want to keep the fish in that temporary tank to convalesce.
Also you’ll need to throw out filter cartridges and clean your filter very well.
It’s a pain but it will be worth it

 

[Byron]

The issue that killed the fish was the pH fluctuation due to using chemicals, period. Please.

The "cycling" had nothing to do with the pH issue here, though it is probable it weakened the fish which only made things worse, so I am not saying it was/is irrelevant. But the pH fluctuation was the death knell. We do not yet know the GH and KH, and these two are crucial to sorting out the pH issue. I suspect from the pH being 7 in the "spring water" that the water is on the soft side, with little if any buffering (the GH/KH will tell us this), and the pH naturally lowers to the acidic side. That in itself is not harmful because the biological system will keep it at "x" level, if it is not interfered with. I do no5t know all the fish species involved, but loaches and neon tetras were mentioned along the way and these being soft water fish would have had absolutely no issue with a lower pH. The guppies and mollies also mentioned would, but the sudden increase in pH is deadly to mollies, and most other fish for that matter.

Sodium bicarbonate is dangerous. It does not permanently buffer. As for any buffering agents such as crushed coral, this also is not the issue. The first thing is to determine the GH of the water. Selecting fish suited to the GH is preferable to adjusting the GH/KH/pH. Not all fish have the same requirements for these parameters, so once you know the numbers you/we know what to expect and appropriate fish can be considered. There is no point in adjusting the parameters to help the mollies (who need fairly hard water) when this will harm the neons, and probably loaches (depending upon species).

The answer to fish issues is almost never to add any additive/chemical/substance to the water. But it is also crucial to know the parameters you have to work with, and members can help you once we know those numbers.

 

[MrNiceKushBoii]

Patience is key, absolutely. Any idea what the white stuff is though? We have nitrite and nitrate readings in this old water, so there’s a cycle going on. Not sure why that Ph went haywire and this wife stuff appeared. Going to re start and properly cycle, I will be adding Fluval Cyvle. I like that stuff and it seems to work better than anything else. I do need to know what to do about the old filter media and rocks, live plants and such. Not sure if this white stuff is contagious.

White stuff would just be bad water quality makes them produce more of a slime coat I had it with one of my panchax I just added some fungus and finrot remedy and did water changes over the next couple days and slowly cleared up or if you had ich or white spot before you would have to scrub everything and do vacuuming gravel etc

 

[Bruce Leyland-Jones]

Interesting to note those who immediately claim it's all down to some disease and then go onto suggest medications...WITHOUT reading all of the posts, where poor tank cycling and maintenance has already been admitted and identified.
Unfortunately, it's this sort of thinking that makes the likes of Petsmart and Pets at Home their profits.