Water hardness?

[lauraf]

I think I might have touched on this subject elsewhere awhile ago, but can't remember which thread it was in, or, clearly, any information I received. I never had a high water hardness reading when I had my LFS test for things that I didn't test myself at home (and I'm only guessing that when they tested for 'hardness' it was KH they were measuring?). I now have a KH liquid test, and for the last few weeks it is showing at only 2KH. Is this okay? Should I be using a product I was sold a while ago called BioBalance that stabilizes pH, KH and GH? And what is the exact difference between KH and GH, and what do they do?

BTW, my tank is nice and stable, at least in terms of the fish behaviour right now. I'm one who tends to think if it ain't broke don't fix it, but at the same time if I can make things better for my fish and/or plants, I'd like to do so.

 

[Doomhed]

If it ain't broke, don't fix it. The only time I worry about water conditions are if my fish are distressed/sick or if I am raising fry.

I change around 4 gallons (out of 25) a week (16% a week, 64% a month) and overdose on prime by 25%. My PH ranges from 5.5 to 6.5 depending on the time of the week. Water slightly soft, with very expensive driftwood tinting the water ever so slightly even after having been used on and off for years.

I like to think my method works and my fish are happy, although some new arrivals haven't fared as well as the angelfish has.

 

[phin]

I may be mistaken, so someone correct me if I'm wrong, but I believe KH is your carbonate hardness - the amount of calcium in your water, while the GH is your general hardness - the level of total dissolved solids in your water.

Your KH will influence your pH as lower KH means your tank has a lower buffering capacity and is more susceptible to pH swings (not really something to worry much about unless you have DIY CO2 or driftwood or any other things that might also affect pH).

Your GH, or total hardness, is the measure that is mentioned when describing the water characteristics preferred by a fish. However most fish may prefer a certain hardness but will do just fine in water with different parameters. GH is really only a factor in a few species (discus being the main one that comes to mind) and when trying to breed fish.

I might add that GH is composed of KH + other solids, so KH is always less than your GH.

If you aren't trying to breed your fish and all your tank inhabitants seem perfectly healthy and happy then don't mess with your water.

 

[lauraf]

I do have CO2 now and a couple pieces of manzanita hardwood. The only difference in my water reading is I notice my pH has crept higher than it used to be several months ago - like 7.1 vs 6.5.
BTW - My angels breed every nine days, whether I want them to or not!

 

[Avalon]

As related to aquarium use:

KH = buffering capacity of the water, or its ability to resist pH changes.
GH = level of alkaline solids in the water such as calcium, magnesium, etc. It is NOT a measure of total dissolve solids. TDS is a completely different measure and can include compounds outside of GH measurements.

What's it all mean? Not a lot really. pH, KH, and GH are completely overrated in fish keeping in general. Certain fish prefer certain parameters, but they will live in a variety of conditions. Just because you have a low KH does not mean your pH is going to swing wildly and turn your water into battery acid or bleach. Fish are also very tolerant of heavy pH swings that follow proper/natural chemistry. Proper breeding requires certain parameters, but fish are fish, and they will breed regardless.

I personally prefer "softer" waters with a lower KH and GH, but that's just due to the fish I like and the plants I grow. I've had many fish thrive in pH's of 5 as well as 9. Neutral (7) is not exactly ideal if you want to nit pick, but there's certainly nothing wrong with it. I think fresh, well oxygenated water is best.

 

[Doomhed]

Exactly Avalon. Personally, I have more luck between 5.5 and 6.2. Honestly, PH is the most useless thing to measure.

I have natural 6.0 from the tap with low GH and high KH, which means I essentially have perfect water for discus. I can't wait to move to a new apartment so I can set up my 55....lol

 

[phin]

As related to aquarium use:

KH = buffering capacity of the water, or its ability to resist pH changes.
GH = level of alkaline solids in the water such as calcium, magnesium, etc. It is NOT a measure of total dissolve solids. TDS is a completely different measure and can include compounds outside of GH measurements.

ahh. i see.

 

[lauraf]

I thought that introducing CO2 could actually cause pH to drop - do I have this wrong?

 

[Newman]

with a KH of 2 it should have dropped... especially at night when the plants do not photosynthesize...

 

[lauraf]

But why is my pH higher now that I have CO2?

 

[Newman]

during the day or night? it would be highest during the day becuase of the effect of increased photosynthesis. vigorously photosynthesizing plants increase the pH becuase photosynthesis is a process that has a tendency to increase the pH of the surrounding water.

 

[lauraf]

Okay, well maybe that explains a bit. I'll try testing pH earlier in the morning to see - I've been doing my water tests later in the evenings these days, as opposed to late-morning.