Hydra Blue Liquid Dye
Pack Size: 95ml (upto 11,875L)Pack Size: 250ml (upto 31,250L)Pack Size: 500ml (upto 62,500L)
Pack Size: 1L (upto 125,000L)Pack Size: 5L (upto 625,000L)Pack Size: 4x5L (upto 2,500,000L)

Hydra Blue Liquid Dye

Our Price:  £17.00
List Price:  £18.55
Saving Of:  £1.55 (8%)
(Inc. 20% VAT)(£14.17 Exc. VAT)
Pack Size:

To preserve colour, use with Hydra Aqua-Brite

See all Hydra Water Dyes

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  (15 Reviews)
  • Works in all ponds and water features, small or large
  • Vibrant blue colour
  • Adds a reflective finish within water features and/or ponds
  • Environmentally friendly and non-toxic
  • Very economical to use
  • Safe for fish, birds, and other wildlife
  • Stops light from reaching the bottom; Reduces or halts algae/weed growth
  • Free of pesticides and herbicides
  • Up to 3 years shelf life

Brand:  HYDRA


  • Works in all ponds and water features, small or large
  • Adds to the reflective quality within water features and/or ponds
  • Environmentally friendly and non-toxic
  • Very economical to use
  • Safe for fish, birds, and other wildlife
  • Quick and simple application
  • Aesthetically appealing
  • Free of pesticides and herbicides
  • For all year round use


Pond weeds, like all plants, algae and many bacteria, use the energy from sunlight to convert carbon dioxide into organic compounds, most typically, sugars. This can often lead to an algae bloom when plentiful resources allow algae to reproduce very rapidly.

This bloom as well as being unsightly can kill off other pond life, i.e. plants and fish. 

Without sunlight, photosynthesis could not occur and life as we know it could not flourish. By using a non-toxic colorant such as Hydra Blue Dye Liquid in the water, you can partially filter sunlight, thereby thwarting the photosynthetic process for the growth of many aquatic weeds and algae's.

Filtering out UV will slow algae and weed growth while transforming lake and pond water to a gorgeous natural blue finish.

By shading underwater portions of your body of water from sunlight, plant photosynthesis is prevented in bottom dwelling plants and weeds. 


Hydra Blue Liquid Dye provides an impressive reflection and colour to your pond and/or water feature and has been used by the likes of landscape gardeners, garden pond/water feature keepers, local authorities, golf courses, and farm ponds.

With it’s quick dispersion quality and high concentration, it’s usage, even in low quantity, is enough to enhance the aesthetic appeal of your pond or water feature. It safely protects and shades your pond or water feature in a blue colour.

Hydra Liquid Dyes are environmentally friendly and non-toxic, meaning they will not harm birds, reptiles, mammals, or fish. So, if you have fish with your pond, adding dye to your pond will not affect them or their health, if anything, the dye will help to protect them. Dye used within ponds with wildlife within will help deter predators, for example, fish will be protected from the predators such as herons.

Water from ponds and water features that have been dyed with any Hydra Liquid Dye, is safe to use as part of irrigation of crops, meaning, if you wanted to change the water in your water feature for example, you can empty it onto your flowerbeds and they will not be effected.


Liquid dyes all work in the same way as food colouring; It dyes something in your required colour. However, liquid dyes used within ponds and water features offer an additional benefit in that they can help reduce plant and algae growth. Dyes do not however, hinder the growth of all aquatic plants, they are recommended for submerged plants such as pondweeds, watermilfoil, and elodea, as well as plants such as water lilies.


  • 5ml treats up to 625 litres (138 gallons).
  • 25ml treats up to 3,125 litres (688 gallons). 
  • 250ml treats up to 31,250 litres (6,875 gallons).
  • 500ml treats up to 62,500 litres (13,750 gallons). 
  • 1ltr treats up to 125,000 litres (27,500 gallons).
  • 5ltrs treats up to 625,000 litres (137,500 gallons). 

*Please note that all images are for illustrative purposes only, Actual colour may vary depending on pond water conditions.

How to use

Administering dye to your pond or water feature is as simple as pouring the correct measurement needed of dye into the water. It will quickly disperse within and around the pond and/or water feature, meaning no need to spray of spread the application our yourself.

Where to use

Water dyes can be applied to ponds and water features of any size, small or large.

Not only can water dyes be added to ponds and water features, they have also been known to be used in small amounts, to glass vases and centrepieces at events and weddings to create drama and aesthetically appealing looks.


NOTE – Use Hydra Aqua-Brite with Hydra Powders and Liquid Dyes. Do not use with chlorine or any other product unless specified by Hydra International Ltd.

Can I use this dye if I have fish in my pond?

Yes. Hydra Liquid dye is food grade dye, and it is completely safe for fish, plants and invertebrates.

My dog sometimes drinks water from my pond. Will it be okay?

Yes, absolutely. Dogs, cats, birds, wildlife - this food grade based dye is safe to be used for drink.

Although, if your dog often drinks pond water - be aware of Blue Green Algae

What happens if we put too much pond dye in our water?

The water will be a deeper shade, and possibly opaque. Over time, rainfall will dilute the colour to the point where it will all be gone. You can also add more water, or partially change water to dilute dye. If emptying the pond is required, the water should be flushed into soil beds – please avoid letting over dyed water get into surface drains or streams. Any water getting into a stream or drain will not be harmful, but it might concern other people if they see odd colour in flowing water - they might report it to authorities as ''pollution''. 

Can water dye leave stains?

Yes, but nothing that can't be washed. It will most likely stain your hands and clothes - that's why it is recommended to wear gloves and protective clothes when using our product. Also, when diluted - it might stain the rock or surface where the water touches, but it is nothing permanent - sunlight will fade any residue.

Is pond dye a good idea?

There is a range of benefits to using pond dyes other than changing the aesthetic of your pond or lake. Pond dyes will limit the sun exposure, promote a balanced ecosystem within your pond or lake and also protect the wildlife living in your pond.

Will pond dye get rid of algae?

Although dyes will not get rid of algae it will reduce the sunlight penertration, this will then reduce the growth becuase it slows the effect of photosynthesis.

How long does dye last in a pond or lake?

Pool dye will last between 4-8 weeks on average depending on your weather.

When should i add the dye to the pond?

To have the best effect and year long benefits you should apply the dye in early spring and then continue to apply every 4-8 weeks depending on rainfall.

Can you swim in a pond that contains pond dye?

Once the pond dye has completely mixed with the water, its is safe for swimmers to jump in, there is no need for you to worry about dying the colour of your skin.

Can we use more than recommended?

Absolutely! Our recommendation is top maximum that our dye can work and still be visible. Please wait 24 hours before adding more solution to the water, as sometimes it takes time for colour to 'settle in''. However, if you are using more than it is recommended - you can expect colour to be darker, more vibrant and water can seem deeper.

In case you overdo it, nothing to worry about. It will fade out with either rainfall or sunlight, or you can dilute water with adding more water or partially changing water. 

Average Rating (15 Reviews):  
Write a Review and share your opinions!

What I was looking for
27 February 2020  | 

I use it for my pond of about 1000 liters &very small amount is enough!
Be careful not to overdo it because the effect is really strong!
I ventured with a drop in a tub in a tub and I had to change the water 😅
Dosed with a syringe it is perfect!


1 of 1 people found this review helpful.

Eliminates blanket weed
20 August 2019  | 

This product will help eliminate blanket weed and will give the pond a lovely blue tinge. It has good clear instructions and doesn’t harm the fish or plants. Excellent products.


3 of 3 people found this review helpful.

Fantastic fountain
19 July 2019  | 

I have a fountain and am very happy with the effect given especially at night when the fountain is lit up. Plus it doesn't stain the stone will order again.


4 of 4 people found this review helpful.

Fantastic effect
19 June 2019  | 

Gives a fantastic shimmering effect to my pond water, very strong so only add a few drops at a time you can always add more if required, seems to last a long time in the water.


3 of 3 people found this review helpful.

Transfomed my pond
22 March 2019  | 

Has transformed the look of my pond. Make sure you wear plastic gloves when using.


3 of 3 people found this review helpful.

Spectacular colour
29 June 2018  | 

I have used water dyes from other companies in the past, so based on that experience I bought a 500ml bottle. This Hydra blue liquid dye is definitely much stronger, it will properly last me a lifetime. Gave a spectacular colour, colour shades change depending on how much you add. I would highly recommend this product to anyone that is look for a blue dye for their pond or water feature.

Was this helpful to you?  Yes  /  No

7 of 7 people found this review helpful.

Highly concentrated
27 April 2018  | 

Very strong product, you only need a tiny amount, gives a great blue in the water showing off my aquatic plants in the shallows.


4 of 4 people found this review helpful.

Great blue colour
11 April 2017  | 

Hydra blue liquid dye has given my pond a great blue colour. It's doing its job very effectively preventing the algae from growing and blocking my pump.


4 of 4 people found this review helpful.

Stopped the algae from growing
10 August 2016  | 

Has 100% stopped the algae from forming in my pond, fish seem to be less anxious as predators can't see them as easily. This product is very strong so add it very gradually, it is easy to overdo it. With each addition, allow at least 20 minutes for the pump to circulate the dye throughout the pond before adding anymore.


7 of 7 people found this review helpful.

Looks great
29 June 2016  | 

My pond is directly in sunlight most of the day so with this product it has really cleared up my pond. The pond looks very impressive and still looks great but I will very be trying out the black liquid dye next time.


6 of 6 people found this review helpful.

Read all 15 customer reviews...

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