# how to maintain gh5 and kh2



## odin79 (8 May 2016)

hi guys!!i make all my water changes from 100% ro water i would like to know how can i maintain a gh around 5 and a kh 2?i have some plants that require really soft water like tonina belem witch i love


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## rebel (9 May 2016)

You can use Seachem equilibrium or a diy/commercial GH booster.

You will need a gH/kH test kit for the initial measurements. Then use a tds meter to standardize and error check.


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## BigTom (9 May 2016)

Or just cut your RO with an amount of tap water, depending on your local water hardness. 

Sent from my HUAWEI GRA-L09 using Tapatalk


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## dw1305 (9 May 2016)

Hi all, 





rebel said:


> You can use Seachem equilibrium or a diy/commercial GH booster.





BigTom said:


> Or just cut your RO with an amount of tap water, depending on your local water hardness.


If you have a hard tap supply (you can get water hardness figures from your water company) ~90% RO 10% tap should be fine.

If you want to make you own re-mineralising agent there is a recipe at <"James' Planted Tank:.... RO ">.

cheers Darrel


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## odin79 (9 May 2016)

thanks so much guys you helped a lot i only use ro water,tap water is way to hard i will use equilibrium and an alkaline buffer i hope i get the ca and mg that i need with equilibrium,the only thing that bothers me is that it contains fe as well so i have to adjust the fe that i`m adding.fe is the only thing that bothers me i grow algae with fe..


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## dw1305 (10 May 2016)

Hi all,





odin79 said:


> i only use ro water,tap water is way to hard


You can almost certainly just cut your RO with some tap water. Have you got a TDS meter?

cheers Darrel


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## macek.g (10 May 2016)

odin79 said:


> hi guys!!i make all my water changes from 100% ro water i would like to know how can i maintain a gh around 5 and a kh 2?i have some plants that require really soft water like tonina belem witch i love



Easy

Example:

For 100l RO

add:
6 grams  NaHCO3(bicarbonate soda) = Kh-2
13 grams CaS04*1/2H20   (calcium sulphate) =Gh-5.021

and
Ca-35.8
Na-16.4
HC03-43
SO4-86


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## odin79 (10 May 2016)

dw1305 said:


> Hi all,You can almost certainly just cut your RO with some tap water. Have you got a TDS meter?
> 
> cheers Darrel


thanks my friend but i cant make the adjustment with tap water...i bought today tds meter 


macek.g said:


> Easy
> 
> Example:
> 
> ...


i`m afraid to use diy ferts and powders..i have read the articles here, i just dont feel confident enough to do it.i use all these that i have in the photo.i used equilibrium and soda


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## Straight Shooter (11 May 2016)

Don't forget to add some Mg if your tap water report states low levels. Mg is also a macronutrient that plants require, measured with a GH test. Seachem Equilibrium contains this, or use MgSO4 (epsom salts).

A ratio of 3:1 Ca:Mg or near to it is advised.


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## odin79 (31 May 2016)

hi guys sorry but i must ask again i use equilibrium but i would like to use ca and mg can you please tell me the portions at 50 litre of water for example?


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## alkm (6 Jun 2016)

odin79 said:


> hi guys sorry but i must ask again i use equilibrium but i would like to use ca and mg can you please tell me the portions at 50 litre of water for example?



To get to GH = 5 you need the following amounts of Ca and Mg in 50 L assuming a 3:1 ratio and the use of RO water:

Magnesium - 0.27 g
Calcium - 1.34 g

However, you will need to adjust the mass depending on what calcium and magnesium salt you use.  For example you could use calcium chloride dihydrate (CaCl2*2H20) and magnesium sulphate heptahydrate (MgSO4*7H2O) in a 3:1 ratio.  You should be able to pick these up off the internet but you need to be certain of the water content.  If you use these two then the amounts will be as follows to get to GH = 5 in 50 L:

calcium chloride dihydrate (CaCl2*2H20) - 4.91 g
(MgSO4*7H2O) - 2.74 g

Cheers


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## dw1305 (6 Jun 2016)

Hi all, 





alkm said:


> You should be able to pick these up off the internet but you need to be certain of the water content.........calcium chloride dihydrate


The magnesium sulphate will be the heptahydrate (.7H2O) because it picks up water from the atmosphere until it is fully hydrated. 

Calcium chloride needs to be stored in an air tight container, because it is deliquescent, and you end up with a liquid which will be at least CaCl2.6H2O.

cheers Darrel


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## odin79 (9 Jun 2016)

thanks so much guys!!!


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