# KH and GH



## RedDragon (Jan 17, 2006)

Hello I have found this site to be extremely helpful. There is one thing that I have not really been able to find. What are good ranges of KH and GH. My setup is:
standard 55 gal
pressurized co2
260 watts of cf
GH - 5
KH -2
PH - 6.6 first thing in the morning (co2 on light cycle)
I am trying to follow the EI method.
Thanks
RedDragon


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## John N. (Dec 11, 2005)

I have my parameters at

KH -5
Gh - 8
pH - 6.8

usually KH between 3-5 is good.
GH not sure if it matters in general depends if you are growing plants that require hard or soft water like tonia.

-John N.


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## trenac (Jul 16, 2004)

I keep the KH in my fish tanks at 3 and 4-6 in my shrimp tanks. KH/GH are not that critical unless you have certain fish that require a softer or hardier water. Most plants can tolerate a wide range of KH/GH, but there is some plants that do better in softer water.


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## BryceM (Nov 6, 2005)

RedDragon said:


> Hello I have found this site to be extremely helpful. There is one thing that I have not really been able to find. What are good ranges of KH and GH. My setup is:
> standard 55 gal
> pressurized co2
> 260 watts of cf
> ...


If you are using pressurized CO2 I'd suggest a KH of around 4 or 5 (3 at a minimum). If your pH is 6.6 with a KH of 2 your CO2 levels aren't nearly high enough. If you get them high enough it would drop your pH into the high 5's. Probably not so good for the fish or plants.

I have a KH of 4.5 and I keep the pH at 6.35-6.40. A low KH will also make your tank susceptible to a pH crash that could kill everything pretty quickly. A KH of around 4 gives you a bit more insurance. KH is easy to raise. Use plain old NaHCO3 (baking soda - NOT baking powder). I use 1 tsp per 10 gallons at WC time to get from KH 1 to KH 4.5.

GH is much less of a big deal. 5 degrees should be perfectly fine. I probalby wouldn't want it any lower though.


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## magicmagni (Aug 19, 2004)

I think GH is still important though not as much as other macronutrients...

It doesn't hurt to put a little GH booster in the tank. This rules out any lack of Calcium or Magnesium. Greg Watson sells some GH booster, Seachem Equalibrium comes to mind too, but I don't like the fact that it has so much postassium in it so I personally like to add 2 teaspoon Epson salts (magnesium sulfate) and 2 teaspoon Kent Turbo Calcium (Calcium Chloride) to my 120gallon every water change just to be sure that I have enough GH.


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