# Too high GH and KH levels



## dzoni (Oct 28, 2005)

Hey guys,

you're still solving problems with low GH and KH, but what about the opposite?

My tap water has

GH: 22 dGH
KH: 12 dKH

Should I decrease it somehow or is it OK?

And also - if I have such high numbers, should I bother with testing Ca? I suppose that I have plenty of both - Ca and Mg, or is it possible that most of it is Ca and I am missing Mg? 

Thanks 

dzoni


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## Raul-7 (Feb 4, 2004)

Your gH is really high. What test kit are you using? The reason is you'll find it difficult to grow most plants or keep fish - except African cichlids - without decreasing your gH somehow. Depending on where you live (whether or not they charge you for waste water) you may find it best to invest in an RO unit.


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## trenac (Jul 16, 2004)

Welcome, Dzoni  

Your KH/GH is not that bad and should be ok, unless you plan to keep fish that need softer water. I once had a KH of 16 and all my plants and fish did just fine (except for the Yo-Yo loaches). I would say that you have enough calcium in the water. There is really no need to buy a test kit for testing calcium.


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## TWood (Dec 9, 2004)

I just moved to a new location where the GH is 24 dGH and the KH is 16dKH. None of what I wanted to grow did very well, and the need to add lots of micros to overcome the uptake limitation just led to more algae. Even when using a mix of RO water and tapwater, the plants stalled out. I've ordered a calcium test kit to get a feel for the Ca:Mg ratio. Meanwhile I'm reconstituting RO water with calcium chloride and magnesium sulfate so I can control things. 

If you don't want to mess with the water, then you'll have to find plants/fish that like it the way it is.

TW


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## New 2 Fish (Dec 31, 2004)

Just a kind of off the wall thought from someone who gardens.... would it be possible where you guys are to collect rainwater and store it for your water changes? Rainwater should be soft, and best of all- free... 
Of course you would need to put a rain barrel together (I've googled them before). Not sure what the nitrates are like in rainwater, but I know that it has more nitrogen than tapwater. Just a thought, and something I'd seriously consider if I had hard water.. but that's just me.


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## Milan (Jul 6, 2005)

dzoni said:


> Hey guys,
> 
> you're still solving problems with low GH and KH, but what about the opposite?
> 
> ...


What is the pH? If it is less than 8, than there is something fishy in there ... Otherwise, it should be OK, IMO ...


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## Raul-7 (Feb 4, 2004)

New 2 Fish said:


> Just a kind of off the wall thought from someone who gardens.... would it be possible where you guys are to collect rainwater and store it for your water changes? Rainwater should be soft, and best of all- free...
> Of course you would need to put a rain barrel together (I've googled them before). Not sure what the nitrates are like in rainwater, but I know that it has more nitrogen than tapwater. Just a thought, and something I'd seriously consider if I had hard water.. but that's just me.


Rainwater is ideal, but it's not always possible to use it for aquariums unless you live in the country where you are absolutely sure there's no smog and it's going to be difficult to collect enough rainwater unless you live in the tropics.


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## dzoni (Oct 28, 2005)

Thanks for replies,

Raul-7 - I am using Sera tests and these numbers are also confirmed by my water company...in fact I don't have any problems with plants (Eleocharis acicularis, Glossostigma, Heteranthera zosterifolia, Limnophila aquatica, Ludwigia repens, etc) except for Hemianthus micranthemoides and Didiplis diandra - these two are growing really poorly. Fish are doing fine as well. 

Trenac - I am worried about magnesium, not calcium.

New 2 Fish - I live in a big city in the middle of Europe, so there is no way, I could use rain water (we have to clean windows every time after rain )

Milan - I don't measure my PH, because any time I try it with my Sera test, I can see on the scale anything from 6,5 to 8. I rather inject as much CO2 as possible till I don't see fish gasping (which I've actually never seen)

dzoni


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## Laith (Sep 4, 2004)

Welcome to APC dzoni!

Join the hard water club! My water is at a KH of 15 and GH of 18/19. Our water GH is made up mainly of Ca but at a GH of 18/19 there should still be enough Mg. However, I do add a bit of MgSO4 at water change just to make sure...


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## dzoni (Oct 28, 2005)

Thanks for welcome Laith,

that's exactly what I wanted to do - add a bit of MgSO4 just to make sure, but I was afraid of raising my GH even more, but if you think that it's ok, I'll try it for couple of weeks and see what hapens...

dzoni


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## Laith (Sep 4, 2004)

I typically add about 5 to 8 grams of MgSO4 to a 200l tank (175l real volume). This adds 2.8 to 4.5mg/l of Mg which is enough, given that there is *some* Mg already in my water.

This amount shouldn't raise the GH by more than around 1 degree.


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