# Water GH Concern !



## Peter F (19 Jul 2009)

I have two tanks that I monitor water quality on a regualr basis. However, I have just noticed that one of the tanks GH has dramatically changed to 180PPM from 40 PPM . The only difference about the tank in question is C02 injection and regular dosing with Tropica fertilisers. Both have the same gravel substrate, live plants, bogwood etc from the same source. 
I have also double checked the the results with differnet test kits to eliminate a bad reading.   

Tap water GH 30 PPM  & KH 40 PPM  

The tank I am concened about:      
PH 7 to 6 with Co2                        
NO3 20 PPM
N02  0 PPM 
GH 180PPM 
KH 40 PPM 

The other tank;
PH 7  
NO3 0.5 PPM
N02  0 PPM 
GH 30 PPM 
KH 40 PPM 

I am concerned if the high GH is detrimental to the fish or plant growth. However, there are no adverse signs.
Also could this be result of the fertiliser dosing and CO2 affecting the reading ?   
I just don't know what is happening or why ! I would only expect the CO2 to change the PH.     

Your thoughts and advice would be appreciated.

Regards: Peter


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## Ed Seeley (19 Jul 2009)

*Re: GH Concern !*

Well your GH is climbing as something is adding Calcium and Magnesium to the tank water!  Usually rising Gh and/or KH can be linked to calcerous substrate or decorations in a tank, but if you have two identical tanks apart from adding the fertiliser that seems unlikely.

If there is definitely nothing calcerous in the tank that could be increasing GH then I would suspect the fertiliser but I don't know what exactly is in that product.  

Either way unless your plants are suffering or the fish show any sign of distress then you don't need to worry.  If you want to reduce the GH then do some 50% water changes as each of those will almost halve the elevated GH according to your readings.


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## Peter F (19 Jul 2009)

*Re: GH Concern !*



			
				Ed Seeley said:
			
		

> Well your GH is climbing as something is adding Calcium and Magnesium to the tank water!  Usually rising Gh and/or KH can be linked to calcerous substrate or decorations in a tank, but if you have two identical tanks apart from adding the fertiliser that seems unlikely.
> 
> If there is definitely nothing calcerous in the tank that could be increasing GH then I would suspect the fertiliser but I don't know what exactly is in that product.
> 
> Either way unless your plants are suffering or the fish show any sign of distress then you don't need to worry.  If you want to reduce the GH then do some 50% water changes as each of those will almost halve the elevated GH according to your readings.



Ed,
Thanks for the prompt reply. 

Regards: Peter


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