Water Conditioner: How It Works and How Much to Use in Aquariums (2022)

Many fishkeepers are unclear about water conditioners for aquariums — how they work, potential risks from overdosing, and the differences amongst the many brands of dechlorinators. Based on the available research and our years of experience using them, let’s talk about the truth behind water conditioners and answer your frequently asked questions.

Do Fish Really Need Water Conditioner?

Maybe. If your drinking water comes from a municipal water supply or other public water system, then most likely it is disinfected with chemicals like chlorine or chloramine to eliminate bacteria, viruses, and other microorganisms that can cause diseases. These chemicals are toxic to aquatic animals and beneficial bacteria and therefore must be removed from the water using a dechlorinator. If you forget to add water conditioner to the tap water, your fish’s gills may become burned, causing them to start gasping or breathing heavily.

If your drinking water comes from a well or other water source that is untreated with chemicals, your aquariums may not need water conditioner. We suggest getting your well water tested to see if it contains any heavy metals because some dechlorinators can help remove them.

Does letting water sit remove chlorine? Yes, chlorine is fairly unstable and will gradually evaporate from water. However, many water treatment plants have begun using chloramine instead of chlorine because it is a more stable disinfectant formed by combining ammonia and chlorine. Chloramine cannot be easily removed from water via evaporation and must be neutralized using dechlorinator. If you are sure your tap water contains chlorine and not chloramine, you can let the water sit for 1-5 days to allow all the chlorine to evaporate. To speed up the evaporation process, aerate the water with an air stone for 12-24 hours or boil the water for 15-20 minutes. Use multi-test strips to measure the water and make sure no chlorine is left.

Water Conditioner: How It Works and How Much to Use in Aquariums (1)

(Video) Prevent Fish/Aquarium Death! You Oughta Know About Water Conditioners!

Air stones connect to an air pump and airline tubing to inject air into the water, agitate the water surface, and speed up gas exchange.

What Does Dechlorinator Do?

The main purpose of water conditioners is to break down chlorine and chloramine and make water safe for fish to inhabit. Almost all dechlorinatorscontain sodium thiosulfate, which reacts to chlorine and chloramine to form harmless byproducts. Sodium thiosulfate looks like rock salt or white powder, and it is often dissolved in water to create liquid dechlorinators. Some water conditioners contain pH buffers, aloe vera to help heal the fish’s slime coats, or extra additives.

Does dechlorinator remove ammonia? Some of them do, as stated on their packaging. The main reason for this is because when dechlorinators are used to treat chloramine, they only react to the chlorine part of chloramine and not the ammonia part. The remaining ammonia ions left in the water are toxic to fish, so some dechlorinators — such as Fritz Complete Water Conditioner, Seachem Prime, and Kordon AmQuel — contain extra chemicals that temporarily lock up the ammonia into an inert state (i.e., ammonium) for up to 24 hours. During this time, the ammonium can be consumed and further broken down by beneficial bacteria in your aquarium and filter.

Water Conditioner: How It Works and How Much to Use in Aquariums (2)

All dechlorinators neutralize chlorine and chloramine, but some contain extra chemicals to treat ammonia, nitrite, and heavy metals.

(Video) The Best Aquarium Water Conditioner

Will dechlorinator remove bleach? Yes, dechlorinator will react to the chlorine in bleach to neutralize it more quickly. The amount of dechlorinator needed depends on the amount and concentration of bleach used. As a starting point, see the directions for neutralizing Purigen chemical filtration media after it has been soaking in a bleach solution.

Is Dechlorinator Harmful to Fish?

Generally speaking, no. However, there are some rare, one-off caseswhere it could be potentially dangerous. The reducing agents in dechlorinator use up oxygen when removing chlorine from the water, and this reaction could be hazardous in poorly oxygenated tanks. For instance, goldfish and discus aquariums can require huge 90% water changes. If you are using water with low oxygen content, adding lots of dechlorinator will further deplete the available oxygen, which can potentially suffocate your fish and beneficial bacteria.

Most fishkeepers try to prevent this from happening by increasing surface agitation in their aquariums to improve gas exchange — the process in which carbon dioxide (CO2) exits and fresh oxygen enters the tank water. However, hobbyists with high tech planted aquariums that inject pressurized CO2 often seek to minimize surface agitation. The intent is to decrease gas exchange so that more CO2 stays in the water for the plants to use. Combine this with the fact that plants only consume CO2 during the daytime and then they consume oxygen at night. Therefore, if you do a water change in the early morning right as the lights turn on, the dissolved oxygen in the water will be at its lowest point. Adding low-oxygen water and dechlorinator could be a recipe for disaster for your aquatic animals.

How Much Dechlorinator Should I Use per Gallon?

Every dechlorinator is different, so follow the dosing instructions on the package. As an example, Fritz Complete calls for 1 ml of dechlorinator per 10 gallons of water. What makes these directions a little confusing is that different municipalities use different amounts of chlorine in their water, so how do you know what is the right concentration for your water? Since the dechlorinator manufacturers do not know how much chlorine your town uses, they deliberately make general guidelines that will hopefully cover everyone’s tap water.

Water Conditioner: How It Works and How Much to Use in Aquariums (3)

(Video) When To Add Dechlorinator During Water Change - (Seachem Prime)

Fritz Complete comes with an easy-to-use pump head for dosing 1 ml of dechlorinator per 10 gallons of water.

How long does it take for dechlorinator to work? Since it takes about 2-5 minutes for chlorine and chloramine to be neutralized, many companies officially state that you should dose the dechlorinator to the tap water in a separate container before adding the water to the aquarium. That being said, we always add the water conditioner directly to the aquarium and then pour in fresh tap water, and there have never been any problems.

Can you put too much dechlorinator in your fish tank? With Fritz Complete, you can treat extremely high levels of chloramine, nitrite, or other toxic chemicals by dosing up to 5 times the recommended amount within the span of 24 hours. This is a very large range that allows much room for error. Just keep in mind that potent concentrations of dechlorinator will quickly reduce the amount of dissolved oxygen, so it may be best to add an air stone for the next 3-4 hours to increase oxygenation in the water.

It wouldn’t be a bad idea to look up the average chlorine usage for your municipality and run a few experiments at home. Let’s say you find out your town uses 2 ppm (parts per million) of chlorine. If you do a 30% water change on a 100-gallon aquarium and you dose 3 pumps of Fritz Complete into 30 gallons of tap water, does the chlorine test register as 0 ppm? Can you get away with less water conditioner, or do you need to dose more pumps to completely eliminate the chlorine? Bottom line: test your water to use the least amount of dechlorinator you can get away and make sure your fish don’t run out of oxygen.

Water Conditioner: How It Works and How Much to Use in Aquariums (4)

(Video) Seachem Prime® - the most concentrated water conditioner on the market!

Use a multi-test strip to quickly measure how much chlorine is in your water.

Many people ask for our recommendation on the best dechlorinator to use, and honestly, we prefer Fritz Complete Water Conditioner because of the super easy pump head that treats 10 gallons of water per squirt. No more carefully pouring out liquid into a bottle cap and hoping you measured the right amount. Just a few quick pumps and you’re done.

FAQs

How much water conditioner should I put in my tank? ›

You should add eight drops of Tetra AquaSafe® per one gallon of water. For example, a two-gallon aquarium will need 16 drops of Tetra AquaSafe®. The 3.3-ounce size has a dropper built into the bottle.

How does aquarium water conditioner work? ›

The main purpose of water conditioners is to break down chlorine and chloramine and make water safe for fish to inhabit. Almost all dechlorinators contain sodium thiosulfate, which reacts to chlorine and chloramine to form harmless byproducts.

How much water conditioner should I use for a 10 gallon tank? ›

Your recommended amount of 5ml to treat 10 gallons, will totally remove all the chlorine & chloramine? Using the recommended amount instantly neutralizes chlorine and chloramines in tap water, restores a fish's natural slime coat, and reduces stress in fish.

How quickly does water conditioner work? ›

This treatment works immediately and takes approximately 24 hours to cycle through depending on the dosage used and tank gallon size. 1.

How much water conditioner do you put in a fish bowl? ›

The manufacturers recommend treating 1 gallon of water with 10 drops of this conditioner.

How often should I put water conditioner in my fish tank? ›

When purchasing your freshwater fish tank, add a water conditioner about 24 hours before adding fish. When changing your tank's water, do so weekly without a filter and every few weeks if your tank has a filter. Don't remove all of the water all of the time.

How long after using water conditioner can I add fish? ›

How long do you have to wait to put fish in the tank after conditioner? As a general rule, you can put fish into the tank 15 minutes after adding the water conditioner. If the tank has proper flow, 2-5 minutes can be enough; however, for larger tanks with improper circulation, you may have to wait for about 30 minutes.

How much water conditioner Do I put in a 5 gallon tank? ›

To detoxify chloramines(break the chloramines bond) Add 1 ml per 5 U.S. gallons (18.9 L) of tap water. Benefits Works instantly to detoxify heavy metals, remove chlorine and break the chloramines bond.

Do I have to put water conditioner in my fish tank? ›

Incoming tap water has chlorine or chloramine added to make it safe to drink. These are toxic to fish. Any time tap water is added to the aquarium, a water conditioner must be used to remove any chlorine/chloramine that is present.

Does water conditioner remove ammonia? ›

Today, water conditioners do so much more than just remove chlorine and neutralize ammonia… They also remove metals like lead and copper, help get nitrates under control and even contain additives like aloe vera that can improve the slime coat of your fish.

How many drops of conditioner do I need for a 3 gallon tank? ›

Use 7 drops per gallon or 1 capful for 10 gallons. Each raised mark in the side of the bottle equals 10 ml.

How long does it take for beneficial bacteria to grow in an aquarium? ›

Normally, it takes 4 to 6 weeks for the growth of beneficial bacteria to complete the nitrogen cycle in a new aquarium.

Can I add fish after 24 hours? ›

Please take into consideration that it is critical to allow the tank to sit for 24 hours before you add the fish. This is purposely done to ensure the accumulation of healthy bacteria buildup inside the tank.

Does water conditioner lower nitrates? ›

Nitrate can be removed from drinking water by distillation, reverse osmosis or ion exchange. A water softener is typically used to treat hard water, but it can also remove nitrate and nitrite with the proper media. Water softeners use an ion exchange process, during which minerals are replaced with sodium.

How much water conditioner should I put in a 2.5 gallon tank? ›

As follows: 1 tsp (or 5 ml) per 10 gal which is the same as 0.5ml (or 10 drops) per gallon of water changed. Therefore if you are replacing the whole 2.5 gallons, you should add 25 drops of aqua safe.

Do you add water conditioner when doing a water change? ›

We already know the importance of adding dechlorinator to our tanks, but when to add dechlorinator during water change is also an important question. It is absolutely safe to add your dechlorinator like, Prime, Safe, or Stress Coat directly into your tank just before adding in your new tap water.

What removes ammonia from fish tank? ›

What should I do?
  • Complete a 25% water change and retest after a few hours.
  • Treat with Ammonia Remover.
  • When at a safe level of 0.0mg treat the tank with Fast Filter Start to boost the bacteria in your filter that process ammonia.
  • Continue to regularly test your water.

What happens if you put too much water conditioner in fish tank? ›

So in most cases, using water conditioner in slightly larger doses than recommended is harmless, but I'd still not recommend doing so. That's because it will bind to the oxygen present in the tank and suffocate your fish. Now, young and healthy fish can most probably fight through it.

Why are my fish dying after a water change? ›

Because the fish live in the water and the changes happen gradually, they adjust to it. When a sudden, large water change occurs, it causes such a drastic shift in the water parameters that the fish often cannot tolerate it and they die.

How do I know if my aquarium ammonia is high? ›

2) What are the clinical signs of ammonia toxicity in fish?
  1. Increased mucous production.
  2. Red or bleeding gills.
  3. Body colour darkens.
  4. Increased respiration rates and fish seem to “gasp” air at the surface of the water.
  5. Secondary infections.
  6. Death.
9 Jun 2020

Can I add water to my fish tank with the fish in it? ›

Even while the fish is in the tank, you can safely add more water to it. “How is that possible?” You may ask. As long as you don't highly agitate your fish, they will not get too stressed about you adding more water.

How do you condition fish with tap water? ›

Can You Use Tap Water for Fish?
  1. Let it Sit for 24 Hours. This is the simplest method, to get rid of the chlorine in the water. ...
  2. Use a UV Light. A UV light is also a great tool that can help you dechlorinate some tap water. ...
  3. Boil the Tap Water and Let it Cool. ...
  4. Pre-Filter with Reverse Osmosis or Carbon Filter. ...
  5. Use Vitamin C.

How many drops of Prime do I need for 5 gallons of water? ›

Seachem Prime Dosage Chart:
Water Volume:Dosage (in mL):Dosage (in drops):
2 Gallons0.2 mL4 drops
3 Gallons0.3 mL6 drops
5 Gallons0.5 mL10 drops
10 Gallons1 mL20 drops
8 more rows

How much Dechlorinator do I need for 1 gallon? ›

However, most of the good dechlorinators - that don't do a lot of unnecessary extra stuff - are dosed between one drop for each two gallons of water an two drops for each gallon of water (that's between about 1 drop for each 8 liters and one drop for each 2 liters).

How much prime do I need for a 10 gallon tank? ›

Info: Seachem Prime dosing instructions
Water Volume1 qt / 1 L10 gal / 40 L
Prime® Dose (mL)0.125 mL5 mL
Prime® Dose (caps)1/25 capful1 capful
Prime® Dose (drops)2.5 drops100 drops

What happens if you don't put water conditioner in a fish tank? ›

THIS IS WHAT HAPPENS WHEN you do Not Add WATER CONDITIONER ...

How long does it take to Dechlorinate water with conditioner? ›

Water conditioner

The amount of time a water conditioner will take to dechlorinate your fish tank depends on the brand of conditioner you purchase. However, most will be effective in about 20 to 30 minutes. Most high-quality water conditioners will remove both chlorine and chloramine in this amount of time.

How can I improve the water quality in my fish tank? ›

Weekly water changes of around 15% - 20% of the total water volume will correct many potential problems in water quality. The water changes will bring fresh mineral rich water into the tank. The fish, plants and bacteria use up the trace minerals in the water and, by adding new water weekly, you replace these minerals.

How do I reduce ammonia in my fish tank naturally? ›

  1. Ways to Lower Ammonia in Aquarium.
  2. Partial Water Change.
  3. Cycle Your Tank.
  4. Improve the Filtration.
  5. Increase Aeration in the Tank.
  6. Upgrade to a Bigger Tank.
  7. Keep Live Plants in the Aquarium.
  8. Add Beneficial Bacteria.
26 Sept 2019

Does water conditioner remove nitrites in an aquarium? ›

TankFirst Complete Aquarium Water Conditioner - Fish Water Conditioner, Instantly Removes Chlorine, Chloramines, Ammonia and Nitrites from Fish Tanks.

Does water conditioner lower pH? ›

No, fitting a domestic water softener will not affect your water pH balance.

How many drops are in a gallon? ›

One gallon = 15,140 drips. One liter = 4,000 drips.

How much conditioner should I use for my betta fish? ›

Directions For Use: Add six drops per pint, 12 drops per quart, or 1/2 teaspoon per gallon of tap or betta bowl water. Instantly detoxifies chlorine, chloramine, ammonia, and heavy metals in betta bowl or tap water, making it safe for your betta.

How long does it take for Aquasafe to work? ›

How long do I have to wait until I can put my fish back in the tank after using Tetra Aqua Safe? It works within 3 to 4 minutes.

What kills beneficial bacteria in aquarium? ›

At higher concentrations, chlorine kills. Unfortunately, chlorine and chloramine will not only harm aquarium fish but can affect the entire aquarium system. These chemicals also kill beneficial bacteria and impair biological filtration.

How can I speed up the bacterial growth in my aquarium? ›

Increase Oxygen Levels

Much like fish, Ammonia and Nitrite consuming bacteria require a lot of dissolved oxygen to thrive. Increasing the dissolved oxygen levels in the water will encourage strong growth in the beneficial bacteria population.

Where does most beneficial bacteria live in aquarium? ›

They keep the water crystal clear and prevent toxic ammonia and nitrite from accumulating. These bacteria live in the filter media and on solid surfaces in the aquarium, such as gravel, rocks, plants and decorations, but it takes time to get them established.

What temperature should a fish tank be? ›

Most tank fish do well at temperatures from 75-80 degrees Fahrenheit (23-27 degrees Celsius), but the needs of specific fish can vary. If your tank is home to just one or two types of fish, it is best to investigate their preferred temperature range and take steps to keep your tank in the middle of that range.

Can you add fish same day? ›

You can add fish as soon as tank water is dechlorinated and to temperature, as long as you add the right bacteria, and the manufacturer states that it is possible to do so. But for the best possible (safest,) results start to Fishless Cycle on the day that the water is dechlorinated and to temperature.

How long can a fish stay in a bag? ›

On average, fish can survive for 6-9 hours in a sealed plastic bag as long as other conditions are met. It is strongly encouraged to only keep fish in a bag for a few hours at most, though.

What is the fastest way to lower nitrates in an aquarium? ›

Removal is simple enough if you carry out large, regular water exchange. Water changes are a sure shot, as they instantly and permanently remove the nitrate from the system. Want to remove 20 percent of the nitrate in the water? Do a 20 percent water change; it's as straightforward as that.

Why do I have no ammonia but high nitrite? ›

Many times the bacteria can quickly handle the overdosing of ammonia and you will get a zero (0) ammonia reading but the nitrite just gets higher and higher. High nitrite is very common when you rush the process or add too much ammonia too quickly. High nitrite inhibits the bacteria and stalls the cycle.

How much nitrate should be in a fish tank? ›

In nature, nitrate in water remains very low, generally well below 5 ppm. In freshwater aquariums, nitrates should be kept below 50 ppm at all times, and preferably below 25 ppm. If you are breeding fish, or are battling algae growth, keep nitrate even lower, below 10 ppm.

How quickly does water conditioner work? ›

This treatment works immediately and takes approximately 24 hours to cycle through depending on the dosage used and tank gallon size. 1.

How often should I put water conditioner in my fish tank? ›

When purchasing your freshwater fish tank, add a water conditioner about 24 hours before adding fish. When changing your tank's water, do so weekly without a filter and every few weeks if your tank has a filter. Don't remove all of the water all of the time.

How does aquarium water conditioner work? ›

The main purpose of water conditioners is to break down chlorine and chloramine and make water safe for fish to inhabit. Almost all dechlorinators contain sodium thiosulfate, which reacts to chlorine and chloramine to form harmless byproducts.

How much water conditioner Do I put in a 5 gallon tank? ›

To detoxify chloramines(break the chloramines bond) Add 1 ml per 5 U.S. gallons (18.9 L) of tap water. Benefits Works instantly to detoxify heavy metals, remove chlorine and break the chloramines bond.

How long after putting water conditioner can I add fish? ›

How long do you have to wait to put fish in the tank after conditioner? As a general rule, you can put fish into the tank 15 minutes after adding the water conditioner. If the tank has proper flow, 2-5 minutes can be enough; however, for larger tanks with improper circulation, you may have to wait for about 30 minutes.

Do you add water conditioner when doing a water change? ›

We already know the importance of adding dechlorinator to our tanks, but when to add dechlorinator during water change is also an important question. It is absolutely safe to add your dechlorinator like, Prime, Safe, or Stress Coat directly into your tank just before adding in your new tap water.

Do you need to use water conditioner in fish tank? ›

Setting up a new aquarium is an event that requires using basic water conditioners to support safe tap water conditions and to ensure you are biologically seeding the tank with optimal species of nitrifying bacteria.

How many drops of conditioner do I need for a 3 gallon tank? ›

Use 7 drops per gallon or 1 capful for 10 gallons. Each raised mark in the side of the bottle equals 10 ml.

How many drops of Prime do I need for 5 gallons of water? ›

Seachem Prime Dosage Chart:
Water Volume:Dosage (in mL):Dosage (in drops):
2 Gallons0.2 mL4 drops
3 Gallons0.3 mL6 drops
5 Gallons0.5 mL10 drops
10 Gallons1 mL20 drops
8 more rows

How much Dechlorinator do I need for 1 gallon? ›

However, most of the good dechlorinators - that don't do a lot of unnecessary extra stuff - are dosed between one drop for each two gallons of water an two drops for each gallon of water (that's between about 1 drop for each 8 liters and one drop for each 2 liters).

Does water conditioner remove ammonia? ›

Today, water conditioners do so much more than just remove chlorine and neutralize ammonia… They also remove metals like lead and copper, help get nitrates under control and even contain additives like aloe vera that can improve the slime coat of your fish.

How long should water sit in fish tank? ›

Water needs to sit for a minimum of 24 hours to dechlorinate. It can actually take almost 5 days for chlorine to evaporate completely from the water, depending on the initial concentration of the chlorine, and the total volume of water. What is this?

Why do you have to wait 24 hours to put fish in tank? ›

It will take about a day for the chemicals to eliminate chlorine and bacteria to bring ammonia and nitrates to healthy levels for fish to live in. Test the water once before setting a 24-hour timer and test it again before adding fish.

How do I know if my aquarium ammonia is high? ›

2) What are the clinical signs of ammonia toxicity in fish?
  1. Increased mucous production.
  2. Red or bleeding gills.
  3. Body colour darkens.
  4. Increased respiration rates and fish seem to “gasp” air at the surface of the water.
  5. Secondary infections.
  6. Death.
9 Jun 2020

What removes ammonia from fish tank? ›

What should I do?
  • Complete a 25% water change and retest after a few hours.
  • Treat with Ammonia Remover.
  • When at a safe level of 0.0mg treat the tank with Fast Filter Start to boost the bacteria in your filter that process ammonia.
  • Continue to regularly test your water.

How do you do a 50% water change in a fish tank? ›

How To: 50% Water Change - YouTube

Can you put to much water conditioner in fish tank? ›

Yes, too much water conditioner can kill a fish. But you'd really have to dump an entire bottle of conditioner into the tank like I did or even more. Even then, most fish wouldn't bat an eyelid (like they have any!).

Does water conditioner make tap water safe for fish? ›

Fish-keepers can make tap water safe for their fish by pre-treating it with a liquid water conditioner, obtainable from the aquarium store or pet store. Choose a product such as StressCoat (made by API) that instantly detoxifies both chlorine and chloramine as well as binding up any heavy metals.

Do you need a filter if you have water conditioner? ›

Water softeners do not filter water, they only remove calcium and magnesium minerals to address hard water. In order to remove contaminants so water is safer for drinking, cooking, and showering — you'll need to use a water filter even if you already have a water softener installed.

Videos

1. Seachem Prime - How to Use on Water Changes
(Palmer Fish Talk)
2. API Tap Water Conditioner | Making tap water safe for your fish
(API Fishcare)
3. Complete Your Aquarium With Fritz Water Conditioner
(Wel-Don Tanks)
4. Are Water Conditioners necessary for your aquarium? "TANK TALK" Presented by KGTropicals
(KGTropicals)
5. The Truth About Dechlorinators
(Aquarium Co-Op)
6. How To Do WATER CONDITIONING For Aquarium || Discus Fish
(Fwrapper Aqua)

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