Water Hardness

[Marclau]

Just tested my tank with the following readings;

Ph Low: 7.0
Ph High: 7.2
Ammonia: 0
Nitrite: 0
Nitrate: 0
Hardness: 90 ppm

Now, based on my general community tank, how does my hardness compare?
Previously it was around 70-80 ppm..........if this is to high, how do I get it down again? Use Bicarb Sod?
If it too low, what do I use? Totally forget hwo to increase/decrease Hardness........

Thanks in advance

 

[petertr]

Which hardness did you measure? Carbon hardness Kh, or German Hardness Gh ?

pH is probably 7.2 as I guess pH Low tops at 7.


Either way, looks like you have fairly middling water.

 

[Marclau]

Which hardness did you measure? Carbon hardness Kh, or German Hardness Gh ?

pH is probably 7.2 as I guess pH Low tops at 7.


Either way, looks like you have fairly middling water.

Sorry, Carbon Hardness......so around 5.05 Gh.........using Aquasonic Hardness test kit.........(Australia)

 

[LauraFrog]

You have a mixture of hard and softwater fish in your tank, so your reading is pretty much ideal for general community care. Hardness is one of the most difficult aspects of water chemistry to adjust. You can add water hardener (rift lake water conditioner at half or reduced dosage) to make water harder, but making it softer is extremely difficult - usually you have to mix it with something like rainwater or reverse osmosis water.

But you don't need to worry, your reading is fine. Some of those fish would be all but impossible to breed in water that hard - tetras will not breed unless the water is virtually mineral free. But if you just want to keep your fish healthy, the readings are perfect.

 

[OldMan47]

A 5 degree hardness, KH is a nice low buffering amount. The bicarb will increase KH, not reduce it. Your KH and pH are a bit low for typical livebearers but is fine for typical egg layers other than the African rift lake egg layers. Those fish like their water hard with a high pH. The trouble with general rules about water hardness for community tanks is contained in the above sentences, There is no value that is good for all fish. The best we can really do is to either get all of the community made up of fish with similar water needs or compromise on water for our fish that won't really be ideal for any of them. I tend to try to get all of my fish made up of those that will suit the water that comes from my tap, that way I am not constantly fiddling with water chemistry and can spend my time enjoying the fish.

 

[Marclau]

Thanks for the quick responses.

Yeah, hardness is one of those areas where it totally depend on your fish.
I have been trying really hard to get it as settled as possible for a generic community tank..............

 

[OldMan47]

Marclau, your swords and guppies would like water with a higher pH and harder water than you have. The neons and serpaes would like the water that you have but would prefer a slightly lower pH. There is no perfect water for a community like that because you have fish with very different preferences. The best advice I can give is to accept the water that you get from your water faucet and don't try to change it. Some of the fish will be more comfortable than others but if you start changing things, all of the fish will be stressed by the attempt. Unless you have a group that all have the same basic needs, it is usually better to not change things at all.

 

[petertr]

Which hardness did you measure? Carbon hardness Kh, or German Hardness Gh ?

pH is probably 7.2 as I guess pH Low tops at 7.


Either way, looks like you have fairly middling water.

Sorry, Carbon Hardness......so around 5.05 Gh.........using Aquasonic Hardness test kit.........(Australia)

Just one thing, Kh and Gh aren't 2 different scales - they measure different things. You need BOTH readings to fully understand your water.