Help/advice needed

[Dthomas91]

Hi guys,

I’ve recently got a new 70L aquarium and had the filter and heater running for a week before buying any fish. When I went to buy the fish from an aquatics chain store I was told the water is fine and that I could buy 10 fish. I ended up buying a mixture of guppies and mollies. I done everything I was advised to do before letting the fish out of the bag into the aquarium and not even 5 mins later the mollies started attacking the guppies which ended up with me losing 4 guppies.

Cut a long story short I went back to the shop today and was told completely different advice about feeding and water testing and pretty much everything to do with the tropical aquarium.

I had my water tested today and the nitrate levels are high, I have now been advised not to feed the fish for a week and add half a capful of bio boost per 10 litres of water everyday for a week.

I also have 15 baby guppies in a breeding net (as I don’t have another tank) but I’m worried if I don’t feed the fish they will die.

Please forgive me as I am new to fish keeping and it was mainly for the kids but any advise would be greatly appreciated.

 

[Aiken Drum]

Ill drop a few posts below this one.

But you have learnt an important aquarium hobby lesson. Many fish store employees wont know any more about keeping fish than you do. And even when they do, their job is to sell you stuff. If what they sell you is pointless, they get to sell you more stuff.

Im going to put a post about the nitrogen cycle and how to cycle a tank below this one. If you have any specific questions, please ask.

 

[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.

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.

 

[Dthomas91]

Thank you so much for the advise.

Would you recommend not feeding the fish for a week as per what the shop advised and not to change the water until the nitrates are under control with the bio boost

 

[Aiken Drum]

Thank you so much for the advise.

Would you recommend not feeding the fish for a week as per what the shop advised and not to change the water until the nitrates are under control with the bio boost

No.

Follow the instructions for a fish in cycle. Do water changes as needed to control ammonia + nitrite combined below 0.5ppm. You have been getting water tested at the store? You will be better off getting a test kit and testing your own water. API freshwater master test kit is a good one to get. It does what you need to test for (pH, ammonia, nitrite, nitrate), is accurate enough for what you are using it for, and as you get 100s of tests from the kit, its more cost effective long run than the cheaper strips.

Until you can test daily, change 1/3 of the water every day.

I think i need to add to my notes about feeding during a fish in cycle. Feed lightly. As much as they eat in 1 minute daily, or 2 to 3 minutes every other day. Fish can survive a week without food, but if you keep up with your water changes its better to feed them something.

Dont worry about nitrate. Nitrate can get pretty high before it will effect fishes health. The water changes you need to do to control ammonia and nitrite should control nitrate as well. If you arent needing to water changes to keep ammonia and nitrite low, changing some water weekly should keep nitrate at good levels. 40ppm nitrate is perfectly acceptable.

A comment about mollys attacking guppies. They are normally considered good tank mates, but sometimes fish are just jerks. Thats not something a fish store is responsible for.

The bio boost you mention is the same kind of product as the Dr Tims and Safestart i mention. It "might" help speed things along, but mostly it doesnt do very much.

 

[Aiken Drum]

Also, if you read the post about the nitrogen cycle, your cycle wont remove nitrate. Its the end product of the nitrogen cycle and the only way to remove it is with your water changes. The bio boost will do nothing to remove nitrate.

If you look on the bottle of bioboost, it doesnt mention anything about nitrate.