Top Fin Bacteria Starter – Our In-Depth Product Review

Alison Page

Alison Page


Top Fin Bacteria Starter

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Adding a bacteria starter to a new aquarium can help to kickstart the biological filter, reducing the time it takes to cycle the fish tank fully.

But what is a bacteria starter? How do these products work? And what’s the best bacteria starter to use?

Read this guide to learn how aquarium bacteria starters work and to read our review of the excellent Top Fin bacteria starter.

Top Fin® Aquarium Readistart Nitrifying Bacteria Starter – Review

  • Suitable for use in freshwater and marine aquariums
  • Packed with beneficial nitrifying bacteria
  • Helps prevent new tank syndrome

Top Fin is a renowned manufacturer of aquarium-related products, including this excellent bacteria starter.

Top Fin® Aquarium Readistart Nitrifying Bacteria Starter
  • Improve the water in your aquarium with Top Fin Readistart Nitrifying Bacteria Starter. Perfect for start-up and maintenance, this product allows for the immediate introduction of fish and naturally reduces ammonia. ?
Check Price

Top Fin bacteria starter is my go-to supplement when I’m setting up a new aquarium! You can also use the starter for the following reasons:

  • to boost the bacteria levels in your tank
  • when introducing new fish or other livestock
  • when performing a partial water change that could deplete existing bacterial colonies
  • following treatment of the tank with medication
  • when routine water tests show that ammonia and nitrites are present
  • when changing biological filter media

This is a great bacteria starter that comes in a 4floz bottle and will treat up to 118 gallons of water, making this product outstanding value for money. To keep the product fresh, store the bottle somewhere cool and dry and use it before the expiry date.

What we like:

  • Helps prevent new tank syndrome
  • Naturally reduces levels of ammonia and nitrite
  • Easy to use and store

Room for improvement:

  • Only available from limited suppliers

How Do Bacteria Starters Work?

You want the water in your aquarium to be safe and healthy for your fish. For that, you need colonies of beneficial bacteria in your filter media.

Nitrosomonas and Nitrobacter bacteria are present on the tank surfaces, in the substrate, and in your biological filter media. Both those species of bacteria are vital for the nitrogen cycle to take place.

Nitrogen Cycle

Through the nitrogen cycle, organic waste is processed and made safe, preventing the decomposing organic matter from releasing harmful ammonia into the tank.

Ammonia is deadly to your fish, causing reddened, bleeding gills, lethargy, poor appetite, Popeye disease, and other health conditions. Excess ammonia in the water also encourages algae blooms, leaving your tank looking untidy and covered in green slime.

Beneficial bacteria process the dangerous ammonia into nitrites, which also harm your fish. But in the next phase of the nitrogen cycle, the bacteria break down nitrites into less harmful nitrates.

Through weekly partial water changes, you can remove excess nitrates from the water.

When Should I Add Top Fin Bacteria Starter to My Aquarium?

If you’re setting up a brand new aquarium, you can’t add fish straight away! You must allow time for the all-important nitrogen cycle to be completed.

The time taken for the tank to fully cycle depends on how long it takes for the bacterial colonies to become established in the tank so that any ammonia produced by the fish is removed from the water.

You can use Top Fin bacteria starter to kickstart the growth of bacterial colonies within a new aquarium and prevent what’s known in the hobby as “new tank syndrome.”

New tank syndrome, or NTS, happens when you add fish to the tank too soon before there are sufficient numbers of bacteria present to process the waste products in the tank. NTS often results in an ammonia spike and mass fish kills.

How Long Does It Take for Beneficial Bacteria To Grow?

Generally, it takes between four and six weeks for the bacteria to grow and complete the nitrogen cycle in a brand-new setup.

Often, adding a bacteria starter can significantly reduce the time you’ll need to wait before adding new fish to your tank.

Bacteria Starters vs. Bacteria Supplements

You might have noticed that you can buy bacteria starters and bacteria supplements in your local pet store. So, what’s the difference?

Well, bacteria starters and bacteria supplements are the same thing and have the same basic function.

Any product that contains beneficial nitrifying bacteria will accelerate your aquarium’s cycling process, as well as help your existing biological filter to keep up to speed with the amount of organic waste in the tank.

In addition, when you treat your fish with over-the-counter medication, that can kill off some of the bacteria in your aquarium. So, when the course of treatment has been completed, you can kickstart your bacteria again by adding a starter.

Large water changes are sometimes necessary, especially if you need to drastically reduce nitrate levels in the tank. Unfortunately, that dilutes the population of bacteria in your aquarium, so it’s helpful to add a bacteria starter product to correct any imbalance.

How Do I Store Top Fin Bacteria Starter?

Top Fin® Aquarium Readistart Nitrifying Bacteria Starter
  • Improve the water in your aquarium with Top Fin Readistart Nitrifying Bacteria Starter. Perfect for start-up and maintenance, this product allows for the immediate introduction of fish and naturally reduces ammonia. ?
Check Price

You should store Top Fin bacteria starter in a cool place away from direct sunlight and other heat sources.

Ideally, you want to keep the product at room temperature. If the temperature is too hot or cold, the bacteria contained in the product will die. Do not store bacteria starters in the fridge!

Bacteria starters typically last for around six months or a bit longer in a cool room. Check the use-by date on the packaging of the product when you buy it. After the use-by date, the product will no longer be effective and should be disposed of.

What Kills the Bacteria in Your Filter System?

There are a few things that can kill off those precious beneficial bacteria in your filter system.


Many of the fish medications that you routinely use to treat your fish for common fish diseases can be fatal to certain species of bacteria in your biological filter media.

To protect your beneficial bacteria, we recommend that you quarantine your fish in a separate hospital tank during treatment.

Tap Water

Tap water contains chlorine and chloramine, which are added to the domestic water supply by water companies. The chemicals are designed to kill harmful bacteria and make the water safe for you to drink and cook with.

Unfortunately, chlorine and chloramine are extremely harmful to your fish and other livestock. Those chemicals also kill the beneficial bacteria in your aquarium, potentially causing an ammonia spike.

So, you must add a dechlorinator product to new tap water before you add it to your fish tank when carrying out a partial water change or setting up a new tank.


Here are the answers to a few of the most commonly asked questions about bacteria starters.

Q: Does Aquarium Salt Kill Bacteria?

A: Many hobbyists routinely use aquarium salt in their tanks to boost fish health. Unlike many fish medications, aquarium salt does not harm beneficial bacteria.

Q: Do Aquarium Bacteria Starters Work?

A: Provided that the product is still well within its use-by date and you store it correctly, bacteria starters can be very effective at eliminating ammonia and nitrites from your aquarium water.

Always choose a reliable, high-quality bacteria starter, such as Top Fin’s product, for the best results.

Q: Do You Need a Bacteria Starter for Your Fish Tank?

A: If you’re setting up a new aquarium, we recommend using a bacteria starter to help kickstart the bacterial colonies in the biological filter media and on the surfaces in your tank.

Q: What Is the Best Bacteria Starter for Aquariums?

A: We recommend Top Fin bacteria starter for your aquarium.

This is a top-quality product that works very well in new tanks, following large water changes, and after a fish medication has been used.

Final Thoughts

Did you enjoy our review of Top Fin bacteria starter and the other information we provided for you? If you did, please take a moment to share the article!

Bacteria starters contain live beneficial bacteria that can form colonies in a new fish tank, helping to process harmful ammonia and nitrite and effectively preventing new tank syndrome.

You can also use Top Fin bacteria starter to boost bacteria colonies following large water changes, after using a fish medication, or when you add new fish to your community, increasing the load on your biological filter.

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