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Seachem Prime vs. Seachem Safe: Which is the Better Water Conditioner?

Seachem has two conditioners that you can use to make your aquarium water safe for fish. So which one is better, Prime or Safe?

You can find out in this comparison guide at Aquarium Blueprints.

Quick Summary

Prime and Safe both have some advantages and disadvantages when compared against each other.

In addition to removing chlorine/chloramine and detoxifying ammonia/nitrites/nitrates, Seachem Prime will also detoxify heavy metals from the tank water.

The formula will also help your fish produce healthy slime coats to ward off infections.

In terms of dosing, we also find that Prime is more convenient, especially if you have an aquarium that can hold less than 50 gallons of water.

The main advantage of Seachem Safe is value. A small 5″ tall 250 g container can treat up to 60,000 gallons, which is 50% more than the biggest Seachem Prime bottle. If you have a lot of big tanks that need to be treated for chlorine, chloramine, ammonia, nitrites and/or nitrates, then you might want to get Safe instead.

Seachem Prime vs. Seachem Safe Comparison Chart

Seachem PrimeSeachem Safe
Package Sizes50 mL

100 mL

250 mL

500 mL

1 L

2 L

4 L
50 g

250 g

1 kg

4 kg
Total Treatable Water Volume50 mL: 500 gallons

100 mL: 1,000 gallons

250 mL: 2,500 gallons

500 mL: 5,000 gallons

1 L: 10,000 gallons

2 L: 20,000 gallons

4 L: 40,000 gallons
50 g: 12,000 gallons

250 g: 60,000 gallons

1 kg: 240,000 gallons

4 kg: 960,000 gallons
Remove Chlorine/Chloramine?YesYes
Detoxify Ammonia/Nitrate/Nitrite?YesYes
Detoxify Heavy Metals?YesNo
Trigger Healthy Slime Coat?YesNo
Measurement Dropper/Cap/Scoop?50 mL: Dropper

100 mL: Cap

250 mL: Cap

500 mL: Cap

1 L: Cap

2 L: Cap

4 L: Cap
50 g: Scoop

250 g: Scoop

1 kg: Scoop

4 kg: Scoop
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Value

Seachem Safe has a massive advantage over Seachem Prime in terms of value. Because Safe is a dry conditioner, Seachem can pack more of the more concentrated formula into a smaller package. As a result, a small 250 grams container of Safe can treat 50% more water volume than a 4 liter bottle of Prime. You can find the package sizes for both conditioners, as well as how much total water volume each can treat, below.

Seachem Prime:

  • 50 mL: 500 gallons
  • 100 mL: 1,000 gallons
  • 250 mL: 2,500 gallons
  • 500 mL: 5,000 gallons
  • 1 L: 10,000 gallons
  • 2 L: 20,000 gallons
  • 4 L: 40,000 gallons

Seachem Safe:

  • 50 g: 12,000 gallons
  • 250 g: 60,000 gallons
  • 1 kg: 240,000 gallons
  • 4 kg: 960,000 gallons

Identical Features

Both the Seachem Prime and Seachem Safe share a lot of common features.

Remove Chlorine/Chloramine

The main function of the two products is being a dechlorinator.

Both have been formulated to remove chlorine and chloramine from the water. Chlorine and chloramine are used to kill potentially harmful parasites in tap water and, thus, making it safe for humans to drink.

However, the same chemicals are deadly to both the fish as well as the beneficial bacteria needed to keep your tank water healthy. So you most likely need a dechlorinator when adding water in your fish tank for the first time or when doing a water change.

Detoxify Ammonia/Nitrate/Nitrite

Prime and Safe will also detoxify nitrogen compounds in your fish tank. Decomposing organic matter, such as fish food and fish poop, will turn into ammonia, which is toxic to your fish.

The aforementioned beneficial bacteria will convert ammonia to nitrites, which is also harmful. Thankfully, another set of bacteria will convert nitrites to the much safer nitrates. With that said, nitrates can cause health issues to your fish in high concentrations of 40 ppm or more.

Seachem conditioners are designed to turn ammonia, nitrites and nitrates into non-toxic forms that are completely safe for your fish. The beneficial bacteria will still then consume converted nitrogen compounds.

Keep in mind that both Seachem Prime and Seachem Safe will only be effective at up to 48 hours when it comes to detoxifying ammonia, nitrites and nitrates. Thankfully, you can re-dose every 24 hours if you need more time for your beneficial bacteria colonies to grow plentiful enough to handle the excess nitrogen compounds.

Seachem Prime Exclusive Features

The Seachem Prime does have a few exclusive features not found in Seachem Safe.

Detoxify Heavy Metals

One of the advantages Prime has over Safe is the ability to detoxify heavy metals that could harm your fish and other aquatic life in your fish tank. These include arsenic, copper, lead and mercury.

Promote Natural Slime Coat Production

Another major advantage of Seachem Prime is that its formula will cause a physiological reaction of your fish, making them produce excess mucus that surround their entire bodies. The slime coat will help protect the fish from infections.

Measurement Dropper/Cap/Scoop

The 50 mL bottle of the Seachem Prime uses a dropper. The bigger bottles (100 mL, 250 mL, 500 mL, 1 L, 2L and 4L) use the cap (the same one that is utilized to keep the bottles shut).

All containers of Seachem Safe (50 g, 250 g, 1 kg and 4 kg) supposedly come with a scoop. With that said, there have been some reports that the product doesn’t come with one.

So, due to the uncertainty of whether or not Seachem Safe comes with a scoop, we give this advantage to Seachem Prime.

Dosage

The amount of dosage Prime/Safe you can add to your tank is different based on the brand as well as the size of the bottle/container.

In general, Seachem Prime is better for dosing smaller fish tanks as you can get an accurate amount with the 50 mL bottle per gallon.

For Seachem Safe, one scoop from the 50 g container will treat 50 gallons. So, if you have a smaller tank, you have to have to carefully divide the dosage amount from the included scoop.

You can find the recommend dosage, based on certain situations, for Prime and Safe below.

Seachem Prime 50 mL Doing Directions:

  • Remove Chlorine/Chloramine and Detoxify Ammonia/Nitrate/Nitrite: 2 drops per 1 gallon (or 4 liters)
  • Remove High Chloramine Concentration: 4 drops per 1 gallon (or 4 liters)
  • Detoxify Nitrite in Emergency: Up to 10 drops per 1 gallon (or 4 liters)
  • Remove Low Amounts of Chlorine and Detoxify Ammonia with Temperature Higher Than 86 °F (or 30 °C): 1 drop per 1 gallon (or 4 liters)

Seachem Prime 100 mL, 250 mL, 500 mL, 1 L, 2L and 4L Dosing Directions:

  • Remove Chlorine/Chloramine and Detoxify Ammonia/Nitrate/Nitrite: 50 mL per 50 gallons (or 200 liters)
  • Remove High Chloramine Concentration: 100 mL per 50 gallons (or 200 liters)
  • Detoxify Nitrite in Emergency: Up to 250 mL per 50 gallons (or 200 liters)
  • Remove Low Amounts of Chlorine and Detoxify Ammonia with Temperature Higher Than 86 °F (or 30 °C): 25 mL per 50 gallons (or 200 liters)

Seachem Safe 50 g Dosing Directions:

  • Remove Chlorine/Chloramine: 200 mg per 50 gallons (or 200 liters)
  • Detoxify Ammonia: 200 mg per 13 gallons (or 50 liters)
  • Remove High Chloramine Concentration: 400 mg per 50 gallons (or 200 liters)
  • Detoxify Nitrite and Nitrate in Emergency: Up to 800 mg per 50 gallons (or 200 liters)
  • Remove Low Amounts of Chlorine and Detoxify Ammonia with Temperature Higher Than 86 °F (or 30 °C): 100 mg per 50 gallons (or 200 liters)

Seachem Safe 250 g, 1 kg, 4 kg Dosing Directions:

  • Remove Chlorine/Chloramine: 1.25 g per 300 gallons (or 1,250 liters)
  • Detoxify Ammonia: 1.25 g per 75 gallons (or 300 liters)
  • Remove High Chloramine Concentration: 2.50 g per 300 gallons (or 1,250 liters)
  • Detoxify Nitrite and Nitrate in Emergency: Up to 5 g per 300 gallons (or 1,250 liters)
  • Remove Low Amounts of Chlorine and Detoxify Ammonia with Temperature Higher Than 86 °F (or 30 °C): 0.625 g per 300 gallons (or 1,250 liters)

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