Neon Tetra pH and Water Parameters Guide

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While they are relatively easy fish to care for, it’s really important that you understand Neon Tetra water parameters if you want to keep them happy.

They’re a species that is pretty sensitive to changes in their water, so it’s not just about setting up the aquarium in the first place – you need to maintain it properly too.

The main Neon Tetra water conditions you need to consider are the temperature, the pH level, and the water hardness.

These should be set correctly before you introduce your Neons, but there are easy ways to adjust and create the perfect habitat for them.

Read on to learn more.

What water parameters do Neon Tetras need?

In the wild, Neon Tetras are usually found in soft, slightly acidic water. So, the water temperature should be between 75 and 80°F, the pH between 6.0 and 7.0 (ideally 6.5), ammonia and nitrite at 0 ppm, nitrate below 20 ppm, and a water hardness no more than 10 dGH.

(Here’s a useful guide to lowering ammonia in your tank, in case your water test shows high levels of ammonia in your tank.)

While these are considered the perfect conditions, the fish can survive in water that’s a couple of degrees cooler, or with a pH just above 7.0. What’s more important with Neon Tetras’ water parameters is making sure it stays consistent once they are thriving.

Neon Tetra parameters are slightly different if you’re breeding the fish. For that, you want to make sure the pH is a little lower, between 5.0 and 6.0, and the temperature should be between 72-75°F.

Neon Tetra pH

While Neon Tetras live in more acidic water in their wild habitat, it’s best to keep aquarium pH levels between 6.0 and 7.0 for them. The ideal Neon Tetra pH level is 6.5, which is just slightly acidic.

(For breeding Neon Tetras you’ll want a separate tank that’s slightly more acidic, between 5.5 and 6.0 pH.)

It’s important to make sure that the pH levels are kept steady at this level. In the wild, the Neon Tetra pH range is lower, between 4.0 and 4.5 in some places. However, using water of that pH in an aquarium could upset the balance of your ecosystem, killing any bacteria in the water and then impacting the Tetras’ quality of life.

Consistency is also key, as spikes in your Neon Tetra water pH could cause them to die.

When you’re preparing your aquarium for the first time, if the water’s pH is too high and it’s more alkaline than acid, you can lower it in a number of ways.

The most natural way to do this is to just leave the water in an unsealed container for a few days. It’ll aerate, drawing in carbon dioxide which in just a few days could lower the pH by 0.5.

Driftwood and peat moss are other natural options – the driftwood will slowly release carbon dioxide, while peat moss will remove bicarbonates which cause the pH to rise. You can buy peat moss fairly cheaply from Amazon (click here to check the price).

Alternatively, you can add chemicals to the water to lower the pH instead.

If the water is too acidic, your first step will be to remove anything which could be contributing, such as driftwood. Otherwise, check your filter to make sure it’s working properly, and if it’s still too low then replace the water with fresh, dechlorinated tap water, giving it time to aerate if the pH is a little too high before you introduce the fish.

Can Tetra live in high pH?

Tetra should be kept in water that’s slightly lower on the pH scale, between 6.0 and 7.0, but can live in water slightly higher than that. If the pH is above 8.0 it’s unlikely Tetra will thrive, but can be comfortable between 7.0 and 8.0.

It’s important you keep testing your water to ensure it remains within the acceptable boundaries, but only take action to lower the pH of the water if your fish are showing signs of stress, such as swimming erratically, hiding away, or looking unwell.

A sudden change in pH will be more harmful to Tetra fish than a water pH that’s slightly above the best conditions.

Neon Tetra water hardness guide

Neon Tetras need soft water to survive. The ideal Neon Tetra water hardness should be between 2 to 10 dGH and between 1 and 2 dKH. Ammonia and Nitrite need to be kept at 0 ppm, with Nitrates below 20 ppm.

The carbon hardness (KH) is linked to the pH level of the water as it is measuring the carbonate and bicarbonate ions – a higher KH will also mean a higher pH. You can lower both by adding peat moss which will remove the bicarbonates from the water.

What is the best temperature for Neon Tetras?

Neon Tetras are tropical fish that live in the Amazon River and other South American waters, so need a higher temperature for their water. It needs to be between 75 and 80°F so you’ll need a heater to keep the water within that range.

You’ll also need to make sure that, during water changes, the new water is as close to the existing temperature as possible and that you add it slowly so that you don’t cause any shock to the fish.

Read more: Neon Tetra Temperature Guide

How to regulate your Neon Tetra tank temperature

There are some great aquarium heaters available from pet stores and online, but there is a product that many fish owners are turning to that is something of a game-changer.

Inkbird ITC-306A WiFi Temperature Controller

  • Protects fish from overheated water
  • Dual display window; displays measured and set temperature at same time
  • High and low temperature alarms
  • Heating time can be set from 1-72 hours if needed

It’s difficult to avoid temperature swings that can be harmful to fish, especially when your room experiences high temperatures in summer or the temperature drops in winter.

Unlike regular tank heaters, the Inkbird allows you to keep on top of your water temperature with a number of unique features.

You can pair the aquarium temperature controller with your phone via 2.4GHz Wi-Fi the INKBIRD app will alert you with push notifications if it senses a problem.

The aquarium temperature controller is equipped with 2 relays to ensure that the power can be turned off under any circumstances, this will protect your fish from being hurt by overheated water (US Socket Only).

The heating time can be set according to your needs from 1 hour to 72 hours, and the controller will alarm if water can not be heated to the setting temperature within the specified time.

If you want complete peace of mind, this product takes total care of your Tetras’ water temperature.

Are Neon Tetras sensitive to water changes?

Neon Tetras are very sensitive to changes in the water parameters and will become stressed and unwell if the conditions aren’t properly maintained. It’s important to check the water 1-2 times per week with an aquarium test kit to make sure there are no sudden changes.

Because they’re so sensitive to small changes in the water, it’s important to never introduce them to a newly cycled tank. Only a matured tank is appropriate, and routine water changes should be kept to between 10-20% once a week.

Read more: How long does water conditioner take to work?

Despite their sensitivity to changes in the water parameters, Neon Tetras are otherwise seen as a good fish for beginners, since they’re hardy in other ways and quite resistant to disease.


Can Tetras live in 7.6 pH?

7.6 pH water isn’t ideal for keeping Tetras, but they can adapt to it, and should survive. Any pH above 8 is likely to be an issue, but 7.6 is close enough to neutral that they will be fine.

If your Neon Tetras are already in 7.6 pH water, don’t try to lower it – a consistent pH is more important.

What is the best pH for Tetras?

The ideal pH for Tetras is around 6.5 but anything between 6.0 and 7.0 is considered good. Wild Tetras are used to a much lower pH, but captive ones have been bred to adjust to only slightly acidic water.

Do Tetras like lower pH?

Tetras in the wild prefer a low, acidic pH, with the Amazon River and its connected streams at around 4.0 to 4.5. Captive Tetras are better suited to a slightly higher pH but still on the acidic side of the scale, between 6.0 and 7.0 with a sweet spot of 6.5 being best.

Can Neon Tetras live in pH 8?

Neon Tetras may be able to survive in a pH of 8.0 but it’s not great and they may get stressed by the water condition, causing them to potentially die. Neon Tetras prefer slightly acidic water below 7.0, and once water is as high as 8.0 it isn’t suited to them.

Can Neon Tetras live in 7 pH?

Neon Tetras should be fine living in neutral 7.0 pH so long as it stays consistent. The recommended pH for keeping Neon Tetras is between 6.0 and 7.0 so while it would be better slightly lower, 7.0 is still within a good range.

Is a 7.6 pH too high for Tetras?

Tetra fish thrive in water with a pH between 6.0 and 7.0 so if you’re preparing an aquarium with a pH of 7.6, it would be better to lower it. If your Tetras are already living comfortably in water of 7.6 pH don’t try to adjust it – it’s better to leave it as it is.


It might sound like there’s a lot of work involved in getting the right water parameters for Neon Tetras but providing you set up your aquarium correctly, things shouldn’t change too drastically. They’re considered a great fish for beginners, which they wouldn’t be if you had to constantly make changes to their setup to keep them alive.

That doesn’t mean you can get complacent though – I would recommend you test the water on a regular basis to keep an eye on it, at least once a week using an aquarium testing kit.

This is the one I use (click to check price on Amazon) – it helps me spot any changes before they cause my fish any stress, allowing me to keep them happy and healthy for longer.

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