free delivery over £120

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Orders under £20 are subject to a £5 surcharge*

free delivery over £120

Orders under £20 are subject to a £5 surcharge*



100 in stock (can be backordered)

Buy to earn 14 Delta Points!

NT Labs Hardness test GH/KH

The NT Labs Hardness Test Kit includes both KH and GH Tests, giving you a great insight into your water quality.

What is KH?

KH is the total alkalinity of your water, or also known as the carbonate hardness of your water, which is the buffering ability of the water. A good buffer means you are less likely to find sudden pH changes, and ensure your water is more stable.

What is GH?

The GH is general hardness, which is hte measure of the minerals that are dissolved in the water. This identifies the water as hard or soft, with much more minerals in hard water, which is what causes limescale build up in hard water araea. Not only will this affect your kettle, but your pond filter or aquarium as well!

With the NT Labs Hardess Test you can measure these to ensure your aquarium is stable and in good condiition, using the simple liquid drops. Ideally, your KH level, which is measured as dKH, should be least 4 dKH, though ideally around 6 - 8 dKH. If you find that your water is lower, you can use a buffer to stabilise this and ensure your pH level is stable long term too. The GH level is measured as dGH, and would ideally be between 8 - 12 dGH for Ponds, though will vary for aquariums depending on the fish you are keeping. For example, South American Cichlids like Kribs and Rams would prefer a softer water, with a lower dGH level, whereas African Cichlids like Malawis will need it much higher.

This Hardness Test Kit includes up to 80 Tests and comes with test tubes and liquid reagents. It is suitable for use with any freshwater aquarium, both Coldwater and Tropical, and also Ponds too.

What is Backorder?

Answer: Available on backorder means we do not have the item currently in stock but are able to order it in and get it out to you quickly.

What is your special local delivery

Answer: This is where we can deliver livestock to you ourselves to save it going to a courier. This means it will be handled with optimum care same day within the local area of our shop.

If you have any questions about this product please feel free to contact us and speak to a member of the team.

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If you live within a 10 mile radius of Birmingham University, and your order is £30 or over (not including postage), you qualify for the option to use our Delta Prime delivery service. This means delivery is at a discounted rate and is also hand delivered by ourselves. For livestock this means there’s no overnight shipping, and hand delivered with care by us. Once your order has been placed, we will contact you to arrange time for delivery. Depending on booking slots, orders placed before 12pm, can be delivered the same day or whenever suits you.


Delivery days & times

7 Days a Week: 3pm-7pm


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