Hard Water, Soft Water and Fish

The science behind successful fishkeeping
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Stephen
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Re: Hard Water, Soft Water and Fish

Post by Stephen »

PaulVerrall wrote:
Sun May 10, 2020 12:10 pm
Thanks Stephen, that's very helpful.
Is there a fish site that matches the fish to the water? Or is it just researching each fish.
Thought it'd be a good thing to have on the forum a place people can check their water hardness like you have done, then when they find they have hard water for instance, there's a list that matches species
I have created my own lists and created a datasheet.
550L - Rio Ucayali themed
4 x Biotodoma Cupido, 24 x Thayeria boehlkei, more fish to come ;)

AshLawson
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Re: Hard Water, Soft Water and Fish

Post by AshLawson »

Stephen wrote:
Sun May 10, 2020 13:45 pm
PaulVerrall wrote:
Sun May 10, 2020 12:10 pm
Thanks Stephen, that's very helpful.
Is there a fish site that matches the fish to the water? Or is it just researching each fish.
Thought it'd be a good thing to have on the forum a place people can check their water hardness like you have done, then when they find they have hard water for instance, there's a list that matches species
I have created my own lists and created a datasheet.
Hi Stephen.

To hijack your post a little (which is really useful, thank you!) could you expand on the significance/difference of KH compared to GH and how much of an impact it has. Am I reading right that KH is German Hardness and GH is General Hardness?
I tested today (api hardness test kit) and quite literally one drop of KH test went straight to yellow so I basically have somewhere between zero and 1 degree KH. The GH is 11. PH 6.3.
What should I be most concerned with?
200l 1000x500 planted Amazonian, 24 x Paracheirodon innesi, 10 x Hyphessobrycon megalopterus, 6 x Corydoras Sterbai, 1 x BNP. Still to add a pair of Angels
2 x Fluval U4 internal

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Re: Hard Water, Soft Water and Fish

Post by Stephen »

Both KH and GH are generally in degrees of German hardness written dKH and dGH.
KH is carbonate hardness (taken from the German Karbonat).
KH is the concentration of bicarbonate and carbonate ions present in the water. Often called the alkalinity, does not refer to a pH above 7, or the concentration of OH- ions, but rather the waters capacity to neutralize acids. Very much related to GH because carbonate/bicarbonate ions are often bonded to calcium and magnesium before they are dissolved into the water E.G. calcium carbonate.

GH is the General hardness.
GH is the mineral content of your water, most tests will measure the amount of calcium and magnesium in the water.

Doncaster water is classed as hard at around 13dGH (degrees German) with an average pH of pH7.6
Which town or village near Doncaster do you live?
Something in the aquarium is making your water acidic and using up the KH.
It may be the cycle itself if you have not done water changes to replenish the KH.
Are you using CO2?
Which substrate are you using?
Test your tap water for a direct comparison.

Are you still doing the fishless cycle?
How long has it been?
Have you done any water changes? A low KH will not help with the cycle.
Pre-dissolve some potassium bicarbonate with some water taken from the tank.
5ml of potassium bicarbonate will raise the KH by 1 degree in 200L of water, aim for 4 degrees for a more stable pH.
Potassium bicarbonate is fairly cheap to buy, on ebay 500g costs about £4.50.
A stable pH is more important than a fluctuating pH.

All the best
550L - Rio Ucayali themed
4 x Biotodoma Cupido, 24 x Thayeria boehlkei, more fish to come ;)

AshLawson
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Re: Hard Water, Soft Water and Fish

Post by AshLawson »

I live in Retford. Tap PH is 7.1, I’ll do a Hardness comparison test.
I’m using Liquid Carbon rather than using gas co2 for the plants. Substrate is Fluval Plant and Shrimp Stratum. I’ve not done water changes during the cycle as I was under the impression it was counter productive (reducing the ammonia rather than leaving it for the bacteria to process and thus impacting the results of the tests too)
I’ll look at the potassium bicarbonate I think Lincoln aquatics might have some I can pick up today.
And yes I’m still fishless! Not putting anything living in until it’s stable.
Should I be concerned about the GH of 11 given the Amazonian stock I’m looking for?
200l 1000x500 planted Amazonian, 24 x Paracheirodon innesi, 10 x Hyphessobrycon megalopterus, 6 x Corydoras Sterbai, 1 x BNP. Still to add a pair of Angels
2 x Fluval U4 internal

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Re: Hard Water, Soft Water and Fish

Post by Stephen »

The GH of 11dGH is almost hard but should be fine for many soft water fish species (not all), it is also fine for many hard water fish species (not all).

Just checked Redford water, 11.4dGH with average pH of pH7.67 according to Anglian water.
I also noticed in the report that the nitrate from the tap is fairly high at 35 (legal maximum is 50), nothing to be really concerned about.

As your KH is so low at the moment I would be inclined to do a 50% water change, allow it to settle and then test and top up the ammonia to 2ppm.

The Fluval Plant and Shrimp Stratum is also bringing your pH level down to a more acidic level (according to reviews and product info that I've read).
The reviews (normally by Fluval sponsored websites) also say that this substrate helps support beneficial nitrifying bacteria colonisation.
Personally I am unsure about the Fluval Plant and Shrimp Stratum, if I had a shrimp tank then yes I may use it but it may be a little too light (weight wise) in a tropical fish tank.
The reviews also say that it's great for root formation but plants can be very easily uprooted due to the lightness of the substrate.
They also say that when the substrate is disturbed (as in syphoning off dirt) then the disturbance makes the water cloudy. They also say do not get fish that like to forage or sift through the substrate as they may uproot plants and as they are sifting through, the water also goes cloudy.
In my original set up I had a thin base layer of Fluval stratum (cheap at LFS), this was topped by 1cm of Tropica plant substrate and then capped with 2cm+ of sand.

Hope it helps
550L - Rio Ucayali themed
4 x Biotodoma Cupido, 24 x Thayeria boehlkei, more fish to come ;)

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Re: Hard Water, Soft Water and Fish

Post by krak27kraki »

My DH has been showing 20 ;-( oin the new fish tank. There are no fish added yet but I would be grateful for any tips on how I can soften the water. The ph was also 9.7. I have added the tap safe and easy balance but that did not make any massive changes.. Any idea how can I soften the water? Can I add de-ionised water?

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Re: Hard Water, Soft Water and Fish

Post by Stephen »

The best way to soften the water is by using a RO unit.
You can use DI water.
Reading water is hard at somewhere between 15-18dGH (depending on which area you live).
Your pH can not be pH9.7 it is more likely around pH7.7 (according to Thames water).
550L - Rio Ucayali themed
4 x Biotodoma Cupido, 24 x Thayeria boehlkei, more fish to come ;)

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