New tank - Cycle Issues

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Xgemineye

Aquarium Advice Newbie
Joined
Feb 23, 2022
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Did my tank crash?? I cycled it everything was going great. My nitrites spiked and dropped same with my ammonia and my nitrates were at 20 ppm and I did the three day test.. everything was going great.
 

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How did you cycle the tank? It sounds like you were doing a fishless cycle. How much ammonia where you dosing?

You need to be dosing 2ppm ammonia and 24 hours later see 0 ammonia and 0 nitrite.
 
Maybe I didn’t dose it high enough.. this is my first tank.. and there’s so much information out there.. ����*♀️ I’ll start over.
 
I added a photo right now my nitrites are at 0 my ammonia is 0.25 and nitrates are at 20
 
Lets start over.

What do you understand about the nitrogen cycle?

Are you trying to cycle the tank with fish or a fishless cycle? How are you planning on doing this?
 
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I’m doing a fish less cycle.. i was told at the pet store to do a fish cycle but that didn’t work out I took the fish back. So I’m now dosing with ammonia and about a month in a half I got everything to spike and drop so I did the three day test and I was showing 0.25 ammonia so I panicked and did a 50% water change.. but now I don’t think I was dosing enough.
 
After everything dropped to 0 I was told to do a 3 day test dosing ammonia for 3 days and doing a 50% water change on the 3rd day
 
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.
 
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 fishless cycle uses an ammonia source to replicate the fish waste that a tank of fish would produce. This ammonia source can be pure ammonia, an aquarium specific ammonium chloride product like Dr Tims Ammonium Chloride, a cocktail shrimp or fish food.

Ill assume we are using an ammonium chloride product.

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. If you have an adjustable heater raise the temperature to 28c/82.5f.

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

Dose the ammonia chloride to approx 4ppm and start testing daily for ammonia. Once your ammonia drops below 1ppm redose it back to 2ppm. This may take a couple of weeks.

Start to test daily for ammonia, nitrite and nitrate. Whenever your ammonia drops below 1ppm redose it back to 2ppm.

You should start to see nitrite and possibly nitrate in your daily tests. Over time your nitrite should start to rise and the amount of ammonia should start to drop further. Your ammonia may start to not be detectable in your daily tests. Keep redosing ammonia daily if you see it below 1ppm. Your nitrite may rise off the testing chart. I prefer to keep nitrite within measurable levels so it shouldn’t hurt to do a water change to keep readings on the chart. Remember to add water conditioner whenever you put tap water in the tank. Nitrate should appear in your water test at some point too.

Over time your nitrite should level off and begin to fall in a similar manner to what your ammonia tests did. When you are able to dose ammonia to 2ppm and 24 hours later see 0 ammonia and nitrite you are cycled. At this point you have enough denitrifying bacteria to consume all the ammonia and nitrite of a moderately stocked tank. You may want to continue dosing ammonia for a few days to make sure it continues to consume all the ammonia and nitrite and be sure your cycle has properly established before proceeding.

Your nitrate will likely be very high. Do a big water change to get nitrate down. Preferably below 10ppm. Adjust your temperature to the needs of your fish. Get your fish, acclimate and add to your tank. I would advise stocking lightly to start with and slowly adding fish until fully stocked.

A fishless cycle typically takes 6 to 8 weeks.

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.
 
That makes sense.. I really appreciate it!! I’ll start over maybe it won’t take as long because I already have some beneficial bacteria.
 
Could i ask why you think your fish in cycle didnt work?

We get a lot of people joining with trouble getting cycles to establish, and the vast majority of them have issues with fishless cycle rather than fish in cycles. People don't really understand what to do, they expect it to run to a timetable, etc.

Fish in cycles are generally easier to get established, easier to understand. If you returned fish to the store, it isnt like they died. What went wrong?
 
They all survived but they weren’t producing enough ammonia to get my cycle started.. I had 10 feeder fish in a 20 gallon tank maybe I needed more.. also a lot of people were saying it was inhumane but they seemed fine..
 
10 fish in a 20 gallon tank is way too much for a fish in cycle. 1 small fish/10 gallons. For a fish in cycle you are trying to keep ammonia low, you dont want it getting elevated. How long did you continue with your fish in cycle? What sort of water parameters where you seeing?
 
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.
 
They all survived but they weren’t producing enough ammonia to get my cycle started.. I had 10 feeder fish in a 20 gallon tank maybe I needed more.. also a lot of people were saying it was inhumane but they seemed fine..
This is something that used to be common back in the day. Throw a load of disposable fish in a tank. Let ammonia build up, if fish die replace them. When the fish stop dying you are cycled. Get rid of the feeder fish and then stock with what you intend to keep. Its this practice that has led to fish in cycles being considered inhumane.

Thankfully more is now understood about the nitrogen cycle and how to safely cycle tanks with fish and the practice of stocking tanks to elevate ammonia levels to harmful levels is no longer common.

If done properly a fish in cycle is safe. Stock lightly, keep up with water changes to control waste to safe levels, add new fish gradually as your cycle establishes and you can cycle with fish in a safe manner.
 
Exactly. Nothing wrong with doing a fish-in cycle if done correctly. Nothing inhumane about it, but it can be more labour intensive, on the same hand it also has less issues cycling!

Camera and screen can make things look different. But keep in mind that a lot of the times a trace amount of ammonia on the test will show up as a .25 reading. If you’re early in the cycle it’s not uncommon to see some trace amounts of ammonia if the tank hasn’t been dosed accurately and timely.
 
FWIW.....
.
.I used " Tetra Safe Start Plus" and it seemed to really sped up cycling..
Looked up the difference between safestart and safestart plus, and the difference is purely concentration. So you use less safestart plus for the same effect (or the same dosage adds more bacteria whichever way you want to look at it).

In case people arent aware, tetra safestart was developed by "Dr Tim" Hovenec, so safestart and one + only are essentially the same product.
 
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