Hardness; And Alkalinity V. Ph

[thecommonnate]

This is either a topic of two questions that have nothing to do with each other or are closely related...

First of all, Hardness. In short, I know basically nothing about this other then what it means. Should I bother regulating it (is it possible to regulate it), if so how? How can I test the water hardness?

And second of all, an alkalinity/pH question.

What is the difference between alkalinity and pH<7.0, or is there one?
Does it relate to hardness?

I have a 25ish gallon planted aquarium with 6 tiger barbs, pH 7.6 with no CO2. Thanks in advance

 

[AdAndrews]

you dont need to worry about hardness. and regarding ph, alkaline ph is anywhere from 7 up to 14, and acids are from 7 down, so as long as you dont have an acid ph you will be fine.. the fish you mentioned does not need a certain extreme in hardness or ph, they will do fine in whatever you put them in

 

[waterdrop]

Note that "alkalinity" and "alkaline" are unfortunate words and cause a great deal of confusion!

"Alkalinity" is a word that means "buffering."

"Alkaline" is a word that refers to a solution that is a base (pH above 7.0) rather than an acid.

This causes no end of miscommunications in any field or hobby that deals with water chemistry.

~~waterdrop~~

 

[OldMan47]

Testing hardness and alkalinity is easy Nate. People like API make a test kit that is very easy to use that measures both hardness, GH, and alkalinity, KH. You add some indicator solution to a sample of water and watch for a color change. When you get the color change you have a number of drops used which is the degrees of hardness. If you prefer ppm of hardness or alkalinity, you use a multiplier to get that number. If I recall correctly it is about 17 ppm per degree.
The other question about needing to measure hardness or alkalinity is very different. If you have trouble maintaining your pH in a tank, chances are the alkalinity is fairly low and a test can tell you if that guess was correct. If you are trying to breed fish that require extreme conditions such as very soft water, the test can tell you if your hardness is keeping you from being successful. I find that fish which need very soft water for breeding will thrive in my hard water but will not breed in it. If I didn't know my water was hard, I would waste a lot of time trying to figure out why my soft water fish don't breed for me.
To adjust hardness and alkalinity to higher values is easy as can be, you add in a source of calcium carbonate such as crushed coral and both values will go up. To get softer water that actually has lower total mineral content, you dilute your tap water with RO water. That will reduce both KH and GH.
If you are going to try to breed truly soft water fish, I find that a TDS meter is very helpful for judging my water quality and deciding what mix of RO and tap water to make. A TDS meter measures the amount of Total Dissolved Solids in the water and is usually the limiting factor when people talk about the need for hard or soft water. More often it would be more accurate to talk about high or low dissolved solids. Until recently, measuring TDS was an expensive proposition so hardness became the guiding parameter. In recent times I have found that you can get a functional TDS meter for about $20 which is only about twice the price of a GH / KH test kit but it keeps on working rather than running out when it runs out of drops.

 

[raptorrex]

you dont need to worry about hardness.

but you do! messin with PH, will result in GH and KH being effected. to make any changes to water perimeters, it needs to be "buffered". so you cant "effect" one without it having a knock on effect, down the line.

 

[thecommonnate]

Thank you everyone, this was very helpful.

 

[thecommonnate]

Okay, I have a follow-up question now

1.) KH, or Carbonate Hardness, is a measure of alkalinity. To increase this, I would need a source of carbonate, you mentioned crushed coral in the form of CaCO3. You told me that this would drive up alkalinity and hardness, is that because it ionizes into Ca++ and CO3--? If so, what are the benefits of having calcium in the tank, is it possible to increase hardness using a different metal, (I'm thinking of calcium stains on drinking glasses, I don't want that in the tank!!)?

2.) Is there a way to increase Alkalinity without increasing hardness? I don't want my barbs to breed, and messing with hardness seems like it could trigger them to do so.

3.) Should I mess with Alkalinity? My pH is pretty stationary at 7.6, so I would guess no.

4.) Do alkalinity and Carbonate Hardness mean the same thing?

and, a completely unrelated question:

5.) Can I use API test kits, such as the "freshwater" master test kit, in saltwater aquariums, and vise versa?

 

[waterdrop]

Okay, I have a follow-up question now

1.) KH, or Carbonate Hardness, is a measure of alkalinity. To increase this, I would need a source of carbonate, you mentioned crushed coral in the form of CaCO3. You told me that this would drive up alkalinity and hardness, is that because it ionizes into Ca++ and CO3--? If so, what are the benefits of having calcium in the tank, is it possible to increase hardness using a different metal, (I'm thinking of calcium stains on drinking glasses, I don't want that in the tank!!)?

2.) Is there a way to increase Alkalinity without increasing hardness? I don't want my barbs to breed, and messing with hardness seems like it could trigger them to do so.

3.) Should I mess with Alkalinity? My pH is pretty stationary at 7.6, so I would guess no.

4.) Do alkalinity and Carbonate Hardness mean the same thing?

and, a completely unrelated question:

5.) Can I use API test kits, such as the "freshwater" master test kit, in saltwater aquariums, and vise versa?

No time to do this justice, so I'll just stab at a few things...
No you should probably not mess about with this stuff. The very best choice is almost always to let your tap water be the guide of what pH and basic mineral content you will have as your baseline. The business of altering these basic parameters is something one does under duress, either because really extreme tap water or a tremendous desire to breed certain fish or something like that usually. 7.6 is so nice, you'll be fine I'd think.

1) Crushed coral is the "method of choice" if you want to raise KH/pH with fish in there and -if- you've made the choice to do it, a big if. Ca is one of those "stuff of life" substances. Its the shells and corals, its been crushed into the limestone of the earth from those same layers of shells, its intertwined with evolution and so yes, its doing lots of "good" things usually in aquariums. Both fish and plants benefit from calcium coming in via that same hardness that makes salts. The fish need it to keep equilibrium at cell walls and the plants use it as a nutrient... lots of good stuff.

2) (skipping this, you don't want to increase alk. anyway)

4) Alkalinity and Carbonate Hardness don't mean exactly the same thing, its just that our simple hobby KH kits that are used to measure carbonate hardness actually measure total alkalinity as its a surrogate for c.hardness in our situation and its a simpler test. (maybe more about the various "hardness"es later)

5) No, freshwater and saltwater are separate kits

 

[doktor doris]

Note that "alkalinity" and "alkaline" are unfortunate words and cause a great deal of confusion!

"Alkalinity" is a word that means "buffering."

"Alkaline" is a word that refers to a solution that is a base (pH above 7.0) rather than an acid.

This causes no end of miscommunications in any field or hobby that deals with water chemistry.

~~waterdrop~~

Quite.

Really one is better off using the word Basic instead of alkaline, see-

Wikipedia entry on basic

cheers

doris