All Fish Dead Overnight

[Brodie Becker]

Hmm so going with what the posters above had said, it definitely appears to be a water quality issue that caused the deaths.

Changing 75 % of the water at a time is not a problem, since the beneficial bacteria live on surfaces, not in the water.

When you changed your tank around, what did you change? Did you also do a full gravel vacuum after you stirred up stuff? I have a couple of hypotheses for what happened:

1) in moving your tank contents around, you released partially rotted matter from the substrate into the water column which fouled the tank, especially if it remained cloudy after the water change. Depending on how deeply you dug into the gravel,there could have been anaerobic pockets of decomposing matter which got released.

2) you removed enough substrate / decorations that you took out enough beneficial bacteria to cause a mini-cycle in the tank, leading to an ammonia spike.

Moving forward, it is imperative that you test your water daily, and each time your water tests above 0 for ammonia or nitrites you need to do a 50%-75% water change. Continue this until they both read 0 for three days in a row. You may also purchase bacterial starter from the pet store (Seachem stability or tetra safe start plus,etc - the product will be described as "cycle your tank" or "jump start your cycle" or similar). This will speed up the process of cycling.

Finally, to protect your fish if you are not in a position to do a water change immediately on getting a nonzero reading, you should purchase Seachem prime water conditioner, and use it instead of your preferred water conditioner. It detoxifies nitrites and ammonia for up to 48h, giving you some breathing room on water changes if you have a busy schedule.

Please keep us posted on how your fish do.

Also, regarding what @Sgooosh said about fish compatibility, it is best to match fish with the same water requirements together, ideally those that match your tap water. You can look up fish profiles on seriouslyfish.com to get their parameter information, and you can find out things like water hardness etc from your water company's report which is usually published on their website.

Thanks for the input. I won't be able to get any chemicals, as we are several hours away from the store where I buy my fish stuff. I will keep doing water changes though.

 

[Sgooosh]

It is an activated carbon filter, with a biofilter sponge. I replace the activated carbon monthly. And yes, the substrate was disturbed.

ok. no dont change it that frequent there is a lot of miceroorganisms in your carbon filter too. when you change it you cause mini cycle.

 

[eatyourpeas]

When you disturbed the substrate you ran the risk of releasing a lot of toxins that are trapped in there.

 

[mcordelia]

With regard to the carbon, you don't need to run carbon in a tank unless you are trying to remove specific toxins, like medications. It is best to only use carbon when it is needed, instead of always running it in the tank. I recommend switching out the carbon cartridge for a sponge (run them both in there for a month to transfer over the good bacteria). In the future, if you need to run carbon, get a mesh bag and the "scoop able" carbon instead of a carbon cartridge, and float the bag by your filter outlet. This way you are not disturbing your filter media at the same time.

 

[Colin_T]

Never add chemicals unless you know what the problem is.

If you ever lose a fish, test the water for ammonia, nitrite, nitrate and pH, then do a 75% water and gravel clean the substrate, then try to figure out what killed it.

Post pictures of the fish.

Did you do anything to the tank on the day the fish died or the day before?

What to do if your fish gets sick

If your fish ever looks sick or unwell, then the following steps might help. Test the Water and Clean the Tank. Test the water quality for ammonia, nitrite, nitrate and pH and write the results down in numbers. Check it for general hardness (GH) and carbonate hardness (KH) too if you can, but...

www.fishforums.net

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Before you treat the tank, do the following things.
Work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.

If you have big rocks or driftwood in the tank, remove these so you get a more accurate water volume.

When you measure the height, measure from the top of the substrate to the top of the water level.
You can use a permanent marker to draw a line on the tank at the water level and put down how many litres are in the tank at that level.

There is a calculator/ converter in the "FishForum.net Calculator" under "Useful Links" at the bottom of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating or it will adsorb the medication and stop it working.

Wipe the inside of the glass down with a clean fish sponge.

Do a 75% water change and gravel clean the substrate. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. However, if the filter is less than 6 weeks old, do not clean it. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn.

Increase surface turbulence/ aeration when using salt or medications because they reduce the dissolved oxygen in the water.

 

[Brodie Becker]

Thank you for the help! So, in summary, I'll need to do a 75% water change daily. I will most likely end up replacing the substrate, and was wondering if I could use sand for live plants. Other than that, what should I do for the filter? Activated carbon or no? And should I medicate? I have a general purpose aquarium medication.

 

[eatyourpeas]

As @Colin_T said, do not medicate unless you know what you are dealing with. Start with the water changes and clean glass, and look for signs of improvement.

Replacing the substrate is a big undertaking and I would remove the fish and start your cycle again. Sand can work with plants but will require root tabs to supply the necessary nutrients. Carbon removes medication and nutrients, so @mcordelia has given great advice about when and if to use it. Try changing your filter media to filter floss or sponge and let the BB do the work.

 

[Fish4dawin]

Also what is your GH? That way if you want to ask what fish can go with which, people can advise you.

 

[mcordelia]

because your tank is currently at a low stocking level, now is an appropriate time to change out the substrate in parts if you do not have another tank for your fish to live in in the meantime. Many people successfully use sand for plants, but do plan on getting root tabs every 1-6months depending on the plants you have. Cories and many other bottom fish will appreciate a sandy bottom!

To gradually change out the substrate, plan to do 1/4-1/3 of the tank area each time. Be prepared that you will never get 100% of the gravel out, but most learn to live with it/pick out gravel at water changes as they feel like it. It will be messy, and you may need to do another 75% water change right after you finish if things get very cloudy. I would also recommend getting bacterial starter, and adding a little more than what the directions call for on the bottle each time you change out some of the sand. That way you can compensate for any mini-cycles you might invoke, and it will be safer for the fish. As above, during the process test daily for ammonia and nitrites to see if they begin to rise, and then (you know the drill) daily 75% changes until they read 0

Sorry that you are somewhat at a turning point with your fishtank at the moment, I hope that this will set you up for bigger and better things!

 

[seangee]

Thank you for the help! So, in summary, I'll need to do a 75% water change daily. I will most likely end up replacing the substrate, and was wondering if I could use sand for live plants. Other than that, what should I do for the filter? Activated carbon or no? And should I medicate? I have a general purpose aquarium medication.

I have (inert) sand in all 4 of my tanks with plants. Not a problem at all, although some plants do need root tabs. The easiest way to change substrate is to plan everything carefully and aim to do the changeover within a couple of hours. Take out the fish and put them into a bucket or tub while you work. Include the heater if the temp is likely to drop by more than 1 or 2 degrees.

The bacteria in your filter won't die if you turn it off for two hours. Since bacteria lives on surfaces rather than in the water you can change 100% of the water in the tank safely - don't forget the dechlorinator and to bring the temp up to close to the water you have in the tub. Do monitor for ammonia and nitrites in the first few days as you will lose whatever bacteria is currently in your substrate, but an established filter should only take a couple of days to catch up.

 

[Brodie Becker]

Again, thanks for all the help! I will replace the substrate with sand once I manage to get this figured out.