# Terms gh, dGH, dkh, kh?



## Hilde (May 19, 2008)

I was checking the data on fish to see if they are compatible for my tank. For water hardness I see gh, dGH, dkh, kh. I have a test kit for the kh and gh. The kh and gh is not always the same. I am confused about which test I should do to see if the the fish fix my parameters.

What test do I do, gh or kh to compare with info I see about fish on the web? How do I convert to dgh or dkh?


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## wkndracer (Mar 14, 2009)

Hi Hilde, Boots on the ground answer not Guru but hope this helps.
Usually a parameter specification lists range for a species including temp.,pH, and total hardness. 

77 - 83°F, pH 5.0 - 7.0, 4 - 13 *dh *(total hardness) 

The GH and KH should _individually_ fall within the limits of the *'dh'* range.

The *'d'* in all this is degree. 4dGH = 71.6GH or General Hardness stated as ppm. Short version not scientific each degree equals 17.9ppm


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## Hilde (May 19, 2008)

wkndracer said:


> *dh *is total hardness
> 
> The GH and KH should _individually_ fall within the limits of the *'dh'* range.


My Kh is usually higher than my Gh though so I am uncertain as to what test I should go by, gh or kh?


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## Raul-7 (Oct 17, 2003)

dKH and dGH do not measure the same parameters, dKH measures carbonate hardness (buffer capacity of your water) while dGH measures the total calcium and magnesium content in the water (actual hardness). Both are important in fish health depending on the locality the fish comes from, fish that prefer acidic water (low dKH/pH) usually prefer softer water as well (low dGH). You should be able to find the water parameters specific fish species need on the internet. 

BTW, KH is the same as dKH and GH is the same dGH. The 'd' just stands for degrees as hardness can also be given in ppm and meq/L.


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## Hilde (May 19, 2008)

Raul-7 said:


> BTW, KH is the same as dKH and GH is the same dGH. The 'd' just stands for degrees as hardness can also be given in ppm and meq/L.


Now more confused. What about this forumula? The *'d'* in all this is degree. 4dGH = 71.6GH


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## Raul-7 (Oct 17, 2003)

Hilde said:


> Now more confused. What about this forumula? The *'d'* in all this is degree. 4dGH = 71.6GH


4 *d*GH is 71.6 *ppm* of GH. 

1 degree = 17.9 ppm = 0.36 meq/L


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## jaidexl (Sep 18, 2006)

KH and GH can be measured in parts per million, or German degrees (dH). The difference is dividing or multiplying by 17.9. A KH of 75ppm is the same as 4.2 dKH. 5 dGH is the same as 89.5 ppm GH.

If you want to know what hardness a fish requires, check it's recommended dH (GH/ dGH) at a reputable profile site like fishbase, and set your GH to match. My opinion about KH is to set it low, if you can, for the plants, and let the fish adapt to it. They depend more on a certain GH than KH. That said, many hobby species will adapt to whatever GH you have as well, stability and controlling fluctuation is more important than matching numbers from a site where some guy logged params from a certain collection site, those numbers should not always be considered 'requirements' for the fish. Many have a natural ability to adapt to changing params in the wild, and sometimes require that ability to breed and stay nomadic.


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## lauraleellbp (Feb 3, 2008)

jaidexl said:


> If you want to know what hardness a fish requires, check it's recommended dH (GH/ dGH) at a _*reputable profile site like fishbase*_, and set your GH to match.


www.fishbase.org :smile:


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## Hilde (May 19, 2008)

jaidexl said:


> Stability and controlling fluctuation is more important than matching numbers . Many have a natural ability to adapt to changing params in the wild, and sometimes require that ability to breed and stay nomadic.


Well I agree with not messy with the water to much for when I did I lost my favorite fish, a gold Ram. 

Since my water is soft and alkaline I adjust the parameters slightly with baking soda and peat. Want to breed fish I get, for 1s I am interested only have 5 year life span, so trying to get some that are near the parameters. 

At present only fish that may be difficult are the pair of Dwarf Rainbow fish I got. They were being sold at Pet Supermarket for $2.5 as Runnynose Tetra thus I couldn't pass them.


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## Hilde (May 19, 2008)

lauraleellbp said:


> www.fishbase.org :smile:


Thanks for the info. I shall have to look at that at another time. My stomach is screaming for food.


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## lauraleellbp (Feb 3, 2008)

What are your water parameters straight out of the tap, and also after you've let water sit for 24 hours?

You may not need to alter your water parameters at all.

I'm a little confused why you're using both baking soda and peat; are you trying to make your water harder, or softer?


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## Hilde (May 19, 2008)

lauraleellbp said:


> What are your water parameters straight out of the tap, and also after you've let water sit for 24 hours?
> 
> I'm a little confused why you're using both baking soda and peat; are you trying to make your water harder, or softer?


I don't use them together. It is 1 or the other depending on the fish and the parameters.

Nomally Gh and Kh unreadable with ph8. Yesterday added a 1 tsp of baking soda and the kh went up 3 to 5. Also ph went from 7.2 to 7.6.


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## lauraleellbp (Feb 3, 2008)

Are you adding the baking soda directly to the main tank, or using another container to pre-mix?


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## Hilde (May 19, 2008)

lauraleellbp said:


> Are you adding the baking soda directly to the main tank, or using another container to pre-mix?


I mix it in a measuring cup and then squirt it in with baby's medicine applicator.


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## lauraleellbp (Feb 3, 2008)

IMO you're doing more harm than good that way. You need to remember that fish need stability in water parameters more than anything else. Each time you add your baking soda mixture directly to the tank, you're very quickly changing parameters for the fish inside the tank.

If you want to develop some consistency and stability in the main tank, you should use a separate aerated holding tank (anything will work; another spare tank, a rubbermaid bin, etc) and always mix up the water for water changes in this tank. Then you can test the water in the holding tank to make sure that it matches up with the main tank before doing your water changes. The aeration (just a simple airstone on an air pump will work) is to help keep the water well mixed and from going stagnant in between use.

Because I don't have space available to always keep water stored for water changes (and I've got too many large tanks to make it practical to store water for water changes) my fish just make do with the water I've got. I'd never even try to change my water parameters unless I decided to take up breeding very specialized fish.


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## Hilde (May 19, 2008)

lauraleellbp said:


> If you want to develop some consistency and stability in the main tank, you should use a separate aerated holding tank.


I will putting the water in a 5 gallon bucket and putting it outside for a day.



lauraleellbp said:


> The aeration (just a simple airstone on an air pump will work) is to help keep the water well mixed and from going stagnant.


I have a powerhead inside with a prefilter. I notice it gets hot and possible making the water get hot. Since I have a Rainbow fish that has a spot of ich on it I am leaving it in and put the heater on. Last night got the temp up to 85 F. I noticed the plants suffering so I turned the heater down. The quarantine tank is full so I have to treat the fish in the planted tank so now I am looking for some medicine that I can put in the planted tank for the ick and bacteria on rainbows mouth[/quote]


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## lauraleellbp (Feb 3, 2008)

Temperature is another thing that fish struggle with when changes quickly. You really shouldn't change temperatures more than one or two degrees per day, if possible.

Is this powerhead in your main tank, or in the bucket where you're pre-mixing water for water changes? I meant that the airstone would be good to keep in the bucket for water changes, as that water could go stagnant between use. Also, outside isn't an ideal place to keep your water for water changes. You'll end up with the water parameters changing from rain and/or evaporation as well as possible contaminants from micro-organisms and chemicals (pesticides being a big worry). Do you have any place inside you could store this? Preferably a dark place to help keep down evaporation? Some people keep their water change reservoirs underneath their tank stands, if there's room there.

Good luck with the ich in your tank; there's several commercial medications on the market for ich that are plant-safe so hopefully you can find one of those at your LFS. Be careful about mixing medications if you try to treat the ich and mouth issue at the same time though, as mixing meds can be dangerous.


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## Hilde (May 19, 2008)

lauraleellbp said:


> Be careful about mixing medications if you try to treat the ich and mouth issue at the same time though, as mixing meds can be dangerous.


Well since I barely see the 1 ich spot I will treat that after I get rid of the mouth bacteria, which kills fish faster than the ich. 

You've probably excessed by now that I am bit impulsive by nature.


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