My fish keep dying

[Jstewart248]

My daughter was gifted a 10 gallon tank for her birthday. We put the tank together let it cycle for 48 hours (per the pet stores instructions) before introducing fish. We had the water tested at the pet store prior to adding fish. Everything came back good. We first got 2 Glofish tetras and two Glofish danios. The tetras passed within 24 hours. I noticed they were skimming the top of the water most of the time so I added an air stone to the tank in addition to the filter that the tank came with. I took a second sample of water in to be tested again and it was good as well. I was told they are schooling fish and I needed 5-6 of one species so we got 4 more danios to go with the 2 live fish we still had so 6 total. The fish are still skimming the top of the water. Some more than others but all of them do it at one point or another. 3 of the 6 passed away overnight. And the 3 still Alive were still skimming the top of the water.

I have found the pet store to be useless as far as help/information goes so I am looking to get advice on how to keep the fish alive.

If my thermometer is correct the temp is 78 degrees. And according to the pet store my water parameters have been perfect every time they have been tested. (Last test was yesterday before adding 4 more fish)

 

[Aiken Drum]

There are lots of reasons why fish may be dying.

Im going to start off by saying you cant cycle a tank in 48 hoursp. Cyling a tank typically takes 6 to 8 weeks. You can either cycle a tank before getting fish, which takes more of a process than simply running a tank for a period of time. Or you can cycle a tank with fish in it, that uses a different process. However its unlikely that an uncycled tank is the cause of fish deaths in the short space of time you are seeing. Ill come back to cycling later.

Reasons why your fish could be dying in the short spaces of time you are seeing.

- Lets get the obvious out of the way. Are you using a water conditioner to remove chlorine/chloramine water treatment commonly used by water companies?

- How are you acclimating new fish to the water in your tank? A sudden change in water conditions from the water in bag you brought your fish home in (typically water temperature) can cause shock which can kill fish in a short space of time.

- Possibly the fish where already sick from the store. The stress of moving etc is what killed them. Glofish are notoriously not hardy fish to start with.

These 3 are the most likely causes. Without more information its impossible to say really.

 

[Aiken Drum]

Onto cycling a tank.

What you have been told about cycling a tank is simply not sufficient. As you have never had fish in the tank, all they are testing is tap water, so of course the test shows perfect water parameters. A cycled tank has had waste in it (ammonia), and that waste will process into nitrate. To know if a tank is cycled the store would need to know that the tank has had fish in it, and the tests should show 0 ammonia and nitrite, and some nitrate as nitrate is the end product of the nitrogen cycle. Im guessing their tests showed 0 ammonia, nitrite and nitrate.

Going forward you need to be able to test your own water. Until you are able to do this, change 30 to 50% of the water daily. This will ensure your water is safe for fish until you are able to test the water and determine how often you can get away with changing water.

Ill post some information on the nitrogen cycle so you have some knowledge of whats going on in the tank and also a method of cycling the tank with fish in it.

 

[Aiken Drum]

The nitrogen cycle is the natural processes that go on in your tank that convert ammonia into less harmful substances.

Ammonia gets into your tank through various pathways. Fish waste, decaying uneaten food, and dead, decaying plants are common ammonia sources in an aquarium. Its also possible your tap water is an ammonia source. Chloramine is a common water treatment and when treated with most water conditioners the bond in the chloramine breaks and releases ammonia into the water.

Ammonia can be toxic to fish, depending on how much there is, and what the pH and temperature of your tank water is.

The first stage of the nitrogen cycle is the removal of ammonia. If you have real plants in your tank some of this ammonia will be absorbed as part of their natural growth. Generally though ammonia is consumed by denitrifying bacteria that lives mostly on your filter media. These bacteria consume the ammonia and produce nitrite. Unfortunately nitrite is pretty much as toxic to fish as ammonia.

The second stage of the nitrogen cycle is the removal of nitrite. A different denitrifying bacteria will consume the nitrite and produce nitrate. Nitrate is much less harmful than ammonia and nitrite, and for most aquariums the nitrogen cycle ends there. Excess nitrate is removed through your regular water changes.

A further stage of the nitrogen cycle can also happen, but its difficult to remove all the nitrate from a typical freshwater aquarium. Plants will absorb some nitrate in a similar manner to how it absorbs ammonia to grow. There are also nitrifying bacteria that consumes nitrate and gives off nitrogen gas which will simply offgas from your aquarium. This nitrifying bacteria is difficult to grow in freshwater aquarium.

“Cycling” a tank is the process you go through to grow denitrifying bacteria in your aquarium to consume ammonia and nitrite. You are said to be “cycled” when you have enough bacteria to consume all the ammonia and nitrite that your tank produces and turns all of it into nitrate. If you test the water of a cycled tank you should see 0 ammonia and nitrite and some nitrate.

 

[Aiken Drum]

To cycle a tank you need to grow denitrifying bacteria to consume ammonia and nitrite that your tank produces. The bacteria needs an ammonia source to grow colonies sufficient in size to consume all the ammonia and resultant nitrite and turn it into nitrate which typically you remove through your regular water changes.

A fish in cycle uses fish waste as an ammonia source and regular water changes are undertaken to ensure that water parameters are maintained at relatively non toxic levels.

Set up your tank. Make sure everything is running smoothly. Make sure you have used a water conditioner product with any tap water you have put in your tank. Seachem Prime is a water conditioner that will also detoxify some ammonia for a day or two, so is a good choice for a water conditioner while cycling a tank with fish.

You should have a test kit. Preferably a liquid test kit. It should test for ammonia, nitrite, and nitrate.

In ideal circumstances you should be starting a fishless cycle with a low bioload (number of fish). 1 small fish per 10 gallons/40 litres is a good number of fish, but this can be tweaked a little for fish that are social and don’t do well on their own. Ideally a hardy type of fish. You may have fully stocked (or overstocked) your tank before you knew about cycling. In these circumstances, if its not possible to return fish, you will have to make the best of it.

If you haven’t already done so, add your fish. Acclimate them to the water in your tank before doing so.

Feed lightly to start with. Daily as much as is eaten in 2 minutes, or as much as is eaten in 3 minutes every 2 days. You can increase to full feedings if you are confident your parameters aren’t getting too elevated too quickly and water changes don’t become a daily thing.

Start to regularly test the water for ammonia and nitrite. At least daily. Depending on your bioload you could start to see ammonia quite quickly. Nitrite will likely take a little longer to appear.

Your target should be to keep ammonia + nitrite combined no higher than 0.5ppm by changing water whenever your water parameters exceed this target. 0.5ppm combined is a level of waste that is sufficient for your cycle to establish but relatively safe for your fish.

If you see 0.5ppm ammonia and 0.0ppm nitrite (0.5ppm combined) then leave things be. If you see 0.5ppm ammonia and 0.25ppm nitrite (0.75ppm combined) then change 1/3 of the water. If you see 0.25ppm ammonia and 0.75ppm nitrite (1.0ppm combined) then change 1/2 the water. If water parameters get worse than these levels it may require multiple daily 50% water changes to maintain safe water conditions. This is more likely to happen with a fully stocked tank.

Remember to add water conditioner whenever you put tap water in the tank.

Over time the frequency of water changes and amount you need to change to maintain your ammonia + nitrite combined target will reduce. You can also start testing for nitrate and should see this rising. If you are finding the ammonia and nitrite in your tests are consistently low, and you aren’t already fully stocked, you can add a few more fish. It may take a few weeks to get to this point.

Once you add a few more fish, continue to regularly test the water and continue to change water if you exceed the 0.5ppm combined ammonia + nitrite target. With added bioload the frequency of water changes and amount you need to change may increase again until your cycle has caught up. Again once you are consistently seeing low ammonia and nitrite you can add some more fish. Rinse and repeat with testing, water changes, and adding fish when safe to do so until you are fully stocked.

You can then cut back on water changes to control nitrate only. Typically you want to keep nitrate no higher than 40ppm, but I would recommend changing some water every 2 weeks even if your water test says you don’t need to.

A fish in cycle from an empty tank to fully stocked can take several months.

A good way to speed up this process would be to put a small amount of filter media from an established filter into your filter, or get a sponge from an established filter and squeeze it into your tank water. Perhaps you have a friend who keeps fish who could let you have some? This will seed your filter with the bacteria you are trying to grow and speed up the process.

Another option is bottled bacteria like Dr Tims One + Only or Tetra Safestart. These products wont instantly cycle a tank as they claim but in a similar manner to adding established filter media they can seed your filter with the bacteria you are trying to grow to establish your cycle. These products are hit and miss as to whether they work at all, but are an option if established filter media isnt obtainable and may speed up the process from several months to several weeks.

 

[Alaecreaturae]

Unfortunately, it sounds like that pet shop may have given you misinformation, either accidentally or on purpose. Every time I have gotten a water test from a big box store, I found that the parameters they give me are completely different from when I use my liquid indicators. They mainly use all-in-one strips which are almost always inaccurate. Get an API master test kit, it's worth the money.

Also if your fish are staying near the upper water column that usually means they are stressed or the water quality is poor. Best of luck to you