# Water KH info.



## Martin cape (28 Dec 2012)

Hi guys. 

I am going to be getting a CO2 injection setup going soon. But, I've been reading that the pH in soft water will fluctuate a lot when I do this. 

My tap water has a pH of 7.6 and a KH of less than 1dKH. I will only be injecting CO2 through the door so will the pH change too much? I know the pH will drop as co2 is injected, then rise again when it stops.

Could I raise the KH to say 4dKH using sodium bicarb to stop the pH swing being as severe?

Thanks guys. I'm new to this.


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## DTL (28 Dec 2012)

You might find this article usefull: Water Chemistry & The Planted Tank

I'm in the same situation KH out of the tap is about two. I add 18g Sodium Bicarbonate to every 36 gallon water change to bring it up to KH = 5.

I'd bring it up slowly over several water changes if you already have livestock in your tank.


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## Martin cape (28 Dec 2012)

Really good article that. GH out of my tap is less than 1 too. 

So, really I need to get my KH and GH about 4 degrees. 

So, should I be adding the appropriate amount of sodium bicarb (for KH), Epsom salts and calcium chloride (for GH)

Or do I just add the salts and calcium chloride which raises both?


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## DTL (28 Dec 2012)

I follow what it says in the article:

To sum it up. To raise kH use baking soda. One teaspoon will increase the kH of 50 liters of water (13 gallons) by 4 degrees (68 ppm). 

To raise gH use calcium chloride and Epsom salts. Add them separately or you will end up with calcium sulfate which takes a very long time to dissolve.
0.79 grams of calcium chloride and 0.33 grams of Epsom salts will raise 10 gallons of water about 1° of gH.


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## Martin cape (28 Dec 2012)

Excellent. Thanks for that . 

Was looking at calcium carbonate, insoluble in water though lol.


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## Martin cape (29 Dec 2012)

Gonna practice my maths on 10 litres when I get the salts


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## Martin cape (30 Dec 2012)

Quick question, the 10 gallons, is that US or UK gallons?


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## DTL (30 Dec 2012)

Martin cape said:


> Quick question, the 10 gallons, is that US or UK gallons?


I assumed US since it's an American site.

BTW, I'd suggest you buy a small digital scale 0 - 100g. Ebay is full of them for a few pounds.
You can't be accurate working with dosing spoons IMHO.


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## Martin cape (30 Dec 2012)

Already ordered one  and a metal spatula . 

The chemist in me bringing my work home with me lol.

Right, ill have to recalculate everything lol.


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## DTL (30 Dec 2012)




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## Martin cape (5 Jan 2013)

Alright pal. Which one do I dissolve up first? Epsom salt or calcium chloride?


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## DTL (5 Jan 2013)

I usually do the Epsom salts first. Not sure if it makes any difference!


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## Martin cape (5 Jan 2013)

Just I done some before and the water ended up dead white and cloudy??


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## DTL (5 Jan 2013)

Martin cape said:


> Just I done some before and the water ended up dead white and cloudy??


 
You need to make sure you allow a good time time between adding the Epsom Salts making sure that it's well into solution, before adding the calcium chloride to avoid precipitation, which it sounds like is happening.

Likewise, you need to add the sodium bicarbonate and let that go into solution to achieve yoour target KH, before dosing for GH


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## Martin cape (5 Jan 2013)

Apparently it's coz I have Sodium bicarb in there too, to increase KH also. 

Apparently they react forming sodium chloride. 

Wondering if they can be added separately to avoid this.


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## DTL (5 Jan 2013)

I usually leave about twenty minutes between adds with good circulation in the water


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## Martin cape (5 Jan 2013)

Cool. Ill try that. 

I'm guessing they don't react in the tank once circulated then.


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## DTL (5 Jan 2013)

Martin cape said:


> Apparently it's coz I have Sodium bicarb in there too, to increase KH also.
> 
> Apparently they react forming sodium chloride.
> 
> Wondering if they can be added separately to avoid this.


 
Calcium Sulphate I think. see above - you need to make the adds separately


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## DTL (5 Jan 2013)

Not sure if I've sent you this link before - see paragraph 6

Water Chemistry & The Planted Tank


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## Martin cape (5 Jan 2013)

Yea you sent me that pal. Helped a lot. For some reason though I assumed it was the Epsom salts and calcium chloride that reacted. But just tried again and that's stayed clear. 

So just gotta keep sodium bi carb seperate to them.


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## DTL (5 Jan 2013)

Martin cape said:


> For some reason though I assumed it was the Epsom salts and calcium chloride that reacted. But just tried again and that's stayed clear.
> 
> So just gotta keep sodium bi carb seperate to them.


 
Me too actually, prob why I had a cloudy tank for a couple of weeks before I started separating out each of the doses

Every days a school day 

Good luck


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## Martin cape (5 Jan 2013)

Haha. Good fun though. 

Gotta sort co2 out tomorra. Just need a big spanner lol


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## Ed Seeley (5 Jan 2013)

Please bear in mind the more you mess with the water conditions from your tap the more you will need to measure and keep on top of it.  Personally I used pure RO for planted tanks for years and just added a teaspoon of GH booster per 25l of new water so there was some trace GH.  I left the KH at 0dKH and injecting CO2 never caused me any issues.  If you boost the KH then you will need to keep monitoring it as your filtration will be using it up.

Habe you just tried running the tank without altering your water chemistry before going to the lengths of modifying it?


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## Martin cape (5 Jan 2013)

When I previously had my tank set up in my old house, I had a planted tank. 

Standard lighting for 8 hours, just internal filter with nitrate and carbon filters. 

No ferts, no co2. 

I got a lot of green hair algae on everything and that black beard stuff. 

Plants would grow very narrow small deformed leaves. Moss grew well and Vallisneria but everything struggled. 

I quite like doing things like this, so I don't mind. I do it as my job in a lab too anyway lol. 

Something to keep my occupied. Good hobby to have


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## DTL (5 Jan 2013)

Ed Seeley said:


> Please bear in mind the more you mess with the water conditions from your tap the more you will need to measure and keep on top of it. Personally I used pure RO for planted tanks for years and just added a teaspoon of GH booster per 25l of new water so there was some trace GH. I left the KH at 0dKH and injecting CO2 never caused me any issues. If you boost the KH then you will need to keep monitoring it as your filtration will be using it up.
> 
> Habe you just tried running the tank without altering your water chemistry before going to the lengths of modifying it?


 
Ed, Thanks for your feedback /advice.
Speaking for myself, living in the Glasgow area where we are on record as having the "softest" water in the UK, and having read many articles and posts on the danger of high PH swings due to low KH, and the dependence of plants and fish on the chemicals which contribute to a higher GH level, I chose to make some adds to at least get to the bottom half of the variously recommended levels. Having done this, so far my results have been pretty good (IMHO). Having come this far, I'd be loath to go back to ground zero, however I'm planning another tank in early spring, so I may take your advice and try setting that one up "without the aid of foreign substances". Cheers, David


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## ceg4048 (5 Jan 2013)

The so-call danger of high pH swings to fish and plants is pure fantasy. Almost all successful CO2 injected planted tanks exhibit daily cyclic, massive swings of pH without any ill effects. I and many other people have had high GH for years without any difficulty growing plants.

Cheers,


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## Ed Seeley (5 Jan 2013)

If it isn't broke and it's working for you then keep going but for the poster the best bet might be to go without first.  As Clive says pH swings due to CO2 injection aren't an issue for fish.  However a tank with a huge bioload and very low KH could suffer pH swings due to the effects of filtration and other things in the water and this is where all the myths about pH crashes come from.  In a planted tank it's a totally different ball game IME.


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## DTL (5 Jan 2013)

Both, good info, thx.


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