Freshwater Aquarium Help

[Bigeasy 125]

Hello All,

I am brand new to the forum and need advise please. To give you some background, I have a 37 gallon freshwater and it is currently stocked with about 20 inhabitants. I am not using live plants but do have plastic ones. As far as substrate, I am using sand. This tank was initially set up fishless back in March. I installed a Marineland Pro 275 with prefilter sponge on inlet. Just went through a severe algae bloom and got that cleared up. I changed all the filters and media plus a 50 percent water change. I added a new internal filter with sponges and biological media. Being new to this hobby and after reading up on water care, I see now that I was wrong to just replace all the filtration, especially not rinsing them in aquarium water. I think I am going through a mini cycle. Water parameters are ammonia is 1ppm, nitrate is 20ppm, nitrite is 1ppm, alkalinity is 300, hardness is 75ppm, and ph is 7.8. water temp is around 79 degrees. None of my fish have died and they are swimming vibrantly. I did cut back feeding to every other day. Can anyone provide any advice for my situation. Also I did treat tap water during water changes. Thanks in advance.

 

[Aiken Drum]

Can you give a more detailed timeline on what has happened with your tank.

You mention setting it up fishless back in March but no detail on what you did with the tank between then and getting fish. When did you get fish? What precisely do you have? When did you change the filter media and then change the entire filter? Whats your typical water change schedule?

You are right that changing filter media isnt a good idea. You should rinse it with dechlorinated water or water taken from your tank. Only replace filter media when its falling apart and even then avoid changing it all at once. Good filter media should last years. The exception would be cartridges and chemical filter media which wont last that long.

You arent cycled. You are seeing some nitrate, so if that's not from your tapwater, you are cycled to a degree but not enough to process out all the ammonia and resultant nitrite. You need to complete a fish in cycle. Do you know how to do this? Essentially change some water to keep ammonia + nitrite combined no higher than 0.5ppm.

Immediate action should be water changes. Based on your water parameters you need 2 x 50% water changes. Do them a couple of hours apart if you are able. One today, one tomorrow if you arent able.

 

[Bigeasy 125]

Hello,

Thanks for responding. Well from March to when I added fish in May, I pretty much just checked the water chemistry month as well as 20% water changes monthly. Numbers between this time were averaging 0 ammonia and nitrites. Nitrates we're no higher than .5ppm. Late July is when the algae bloom occurred. I had been tinkering with HOB filter deciding what media I wanted to use. I know, another rookie mistake. Added a UV sterilizer to clear algae bloom. When bloom cleared that is when I made the mistake to replace all the media in the HOB filter, cartridges and bio media. Did not replace inlet prefilter sponge. Add Sicce Shark ADV internal filter so I can get rid of the HOB filter since it is starting to fail already. Now in the Sicce I have sponges, ceramic rings, and zeolite/carbon that are all new. I did rinse them in aquarium water before placing in tank. Getting good aeration and water is crystal clear. Chemistry is the main issue. I know tank has to get cycled again. Made all these changes last Friday. Completed the 50% water change today and added water conditioner. Current fish I have are 4 zebra danios, 4 gouramis, 5 black phantom tetras, and 5 neon tetras. All are not have visible issues. They eat, swim, and play well at this point.

 

[Aiken Drum]

Not that its relevant any more but that 2/ 3 months of running your tank between March and May did nothing useful. If you were trying to do a fishless cycle you need an ammonia source for the beneficial bacteria to feed on and grow so it can support your fish when you get them. This ammonia source can be actual ammonia/ bleach, an aquarium specific ammonium chloride product, a cocktail shrimp or fish food. All you did was spend those months circulating tap water. Your tests never showed anything because you put nothing in the water for the tests to show. I will post something about the nitrogen cycle that will explain in a bit more detail what is going on should you be interested, but in short if there is no ammonia going into the tank your tank cant cycle.

I will also post a method of doing a fish in cycle. This is going to be difficult now you have quite a lot of fish. A fish in cycle should really start with a small amount of fish, 1 small fish per 10g is a good number. You then gradually add more fish as your cycle establishes. Returning most of your fish would be a good idea. But if you are unable/ unwilling to do this you will just have to make the best of things. That will probably mean frequent, big water changes. Maybe daily water changes for a couple of weeks. The fish in cycle method gives detail on how much/ how often to do water changes based on your daily water test.

The UV you mention. UV will kill bacteria in the water. While the beneficial bacteria responsible for your cycle doesn't live in the water (it lives on surfaces like your filter media) it does get into the tank from the atmoshere via the water, then onto your filter media where it can then grow. Having the UV on during the cycling process might kill off the bacteria before it gets to your filter in sufficient numbers to colonise. Make sure its turned off or removed from the tank until your cycle is established. Its OK to have it back once you are cycled if that's your wish.

 

[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.