Water terminology - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 05-09-2012, 07:50 PM Thread Starter
Wannabe Guru
 
green_valley's Avatar
 
PTrader: (11/100%)
Join Date: Sep 2011
Location: California
Posts: 1,098
Water terminology

After this long, I am actually confused about water terminology and I need to get this clear up.

Acidic water
Alkaline water
Soft water
Hard water

I am using pH tester from API. From what I understand, the higher number means more alkaline the water is. The lower the number, the more acidic.

Does soft water means alkaline? and Hard water means acidic? or the other way around?

hahahahha.........shame on me

*************
**** Green ****
*************


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
green_valley is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 05-09-2012, 08:28 PM
Wannabe Guru
 
pejerrey's Avatar
 
PTrader: (12/100%)
Join Date: Dec 2011
Location: Oakland, California
Posts: 1,935
Usually soft/hard water refers to GH. general hardness usually measured by calcium concentration and the more there is in the water is considered harder. This is important for plants but more for inverts to molt or build shells, they also need magnesium. GH boosters have ca and mg combined.

Carbonate hardnes or KH is the concentration of carbonate compounds such as co2 generally that are readily available for plants to use. Too much and you sofocate livestock, too little and you will get algae blooms as the nutrients in the water need to be consumed in relation to the amount of light the tank is getting. Co2 and light are tightly related in planted tanks.

Both GH and KH are measured by ppm(particles per million), mg/l(milligram per liter) and degrees.

So you can say 100ppm of Gh or (mg/l) as you can say 5.58 degrees (dGH). Same with KH.

Degrees is ppm or mg/l divided by ~17.9.

Please correct me if I'm wrong.

*edit: Alkaline/acid only refers to ph.
Although the injection of Co2 will raise the carbon content thus your measurement of KH and at the same time will lower the ph making water more acidic. Adding baking soda to raise KH will make your water alkaline which is the opposite.
In both cases KH is been brought up but the ph is affected differently.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

A heavily planted shrimp tank is possible!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

pejerrey is offline  
post #3 of 7 (permalink) Old 05-09-2012, 08:45 PM
Planted Tank Obsessed
 
Sierra255's Avatar
 
PTrader: (0/0%)
Join Date: Sep 2007
Location: Dickinson, TX
Posts: 306
Acidic and alkaline refers to the pH. pH ranges from 1 to 14. A pH of 7.0 is neutral, neither acidic or basic. Anything with a pH below 7.0 is considered acidic and anything above 7.0 is considered basic, or alkaline. The further away you get from neutral (7.0), the more acidic or alkaline the solution is. Water with a pH of 6.0 is more acidic than water with a pH of 6.5.

The hardness of water has to do with the dissolved mineral content in the water. You'll often see it referred to as GH (General Hardness) and KH (Hardness as a result of dissolved potassium). Hardness is often measured in degrees, and the higher the number, the harder the water. If you see it reported as GH or KH, it is in degrees. If you have really hard water at your house, you will have problems with water spots in your shower or after 5-10 years (usually) your water heater will start to make loud noises when it's heating. This is all due to the minerals in the water coming out of solution. The water spots are the mineral residue left over after the water evaporates. If you have soft water, the water is lacking these minerals dissolved in the water. The hardness of the water doesn't ultimately determine what the pH of it is, but it can have an affect on how it changes (or doesn't change) based on changing conditions in an aquarium. Hard water has a greater buffering capacity and is more resistant to swings in pH than softer water.
Sierra255 is offline  
 
post #4 of 7 (permalink) Old 05-09-2012, 09:16 PM
Planted Tank Guru
 
wkndracer's Avatar
 
PTrader: (68/100%)
Join Date: Mar 2009
Location: Citrus County,Florida
Posts: 6,186
There are several minerals that will effect carbonate hardness and effect tested KH values. CaSO4 acts as buffer, calcium rich cuttlebone will dissolve increasing KH.

"Carbonate hardnes or KH is the concentration of carbonate compounds such as co2 generally that are readily available for plants to use."sorry but this is completely wrong in how it's stated.
pH / KH / CO2 well yes,,, there is a relationship but it's relative to other impurities in the water and not truly accurate. Google will pull a dozen charts (at least) and explanations of the relationship.

If you're using API kits the instructions include the conversions for you.
Each degree (drop of reagent) = 17.848ppm either gh or kh.

2dKH is more than enough buffer to maintain stable pH even on CO2 injected systems. More doesn't hurt but it's not required for stability.

7.0pH is neutral, below that values are acidic, above more alkaline.
The scale is logarithmic. Each degree on the pH scale is a 10x change in value.

pH values really don't tell you anything about hardness values. GH/KH test kits are the answer for those values.

HTH

edit here too LOL. CO2 injection does not add to or effect KH values, it drives pH lower but it's basically a false value. Or a reading of CO2 saturation. Once outgassed the pH rises or rebounds back to the previous readings. Mineral content and tested pH needs to be considered with the water at atmospheric equilibrium. HOPE this makes sense here.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If at first you don't succeed,,, keep kicking it
RubberSideDownOnTheLanding,
2-75g planted, 3-55g planted, 110g w/30g sump, 2018 update returning to sanity (Nutz)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
wkndracer is offline  
post #5 of 7 (permalink) Old 05-09-2012, 10:35 PM
Wannabe Guru
 
pejerrey's Avatar
 
PTrader: (12/100%)
Join Date: Dec 2011
Location: Oakland, California
Posts: 1,935
Thanks for correcting as I asked. Such a friendly attitude too!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

A heavily planted shrimp tank is possible!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

pejerrey is offline  
post #6 of 7 (permalink) Old 05-10-2012, 03:26 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jan 2010
Location: Contra Costa CA
Posts: 11,721
Re post #3
KH is not potassium. K, the chemical symbol for potassium, is from Kalium, a Latin word.
The K in KH comes from Karbonate (a German word), in English: Carbonate. It is a couple of different forms of minerals with a carbon and 3 oxygens stuck on. The CO3 is the carbonate part.
CaCO3 is Calcium Carbonate, a very common material on Earth.
It also relates to bicarbonate, HCO3. This is found in many living systems. You might be familiar with bicarbonate of soda, or sodium bicarbonate, which is baking soda.
The link in the aquarium between carbonate, bicarbonate and carbon dioxide is a bit complex, but here are a few simplified concepts:

Use a separate test for pH, GH and KH. Neither one measures anything the others measure. While there may be links, and related results, the rule is NOT ALWAYS. You can find charts that relate the level of KH and the pH to the level of CO2. These charts are not always accurate, because there are other buffers in the water besides carbonates.

Fish are usually referred to as Soft Water or Hard Water. This is GH. Fewer minerals in the water = soft water. The primary minerals measured are calcium and magnesium. Fish and plants use these minerals, so if the level is really 0, this is a problem. If you need to alter the water to suit the fish it is best to set the GH to the right level first.

KH is a buffer that stabilizes the pH. With high KH the pH tends to be high. With low KH the pH can vary more, depending on what else is in the water. There are other buffers in aquariums, too, but KH is one of the most common. Once you have the right GH in the tank, make the KH pretty much similar, within a couple of degrees.

pH is a ratio of hydrogen to hydroxyl ions, that is H+ to HO- in the water. When there are more H+ the water is called acidic, and when there are more OH- the water is called alkaline. One example of why pH can be important: Ammonia is most common in the aquarium in either of 2 forms. When the water is more acidic, that is low pH, the ammonia is present in the form called Ammonium, NH4, and is less toxic to the fish. They can keep it out of their system easier. When the pH is high, that is alkaline, ammonia is present in the ammonia form, NH3, and is more toxic. It enters the fish through the gills, and is toxic.

Here is the link between GH, KH and pH in natural water systems (and it is not a hard-and-fast rule)
As rain falls over the rocks and seeps through the soil it can dissolve the minerals in that soil and the rocks.
In many places on Earth there are rocks that are high in calcium carbonates and magnesium carbonates. There are different forms of these, some more soluble than others.
If the rain is plentiful it may have already dissolved most of the soluble minerals ages ago, so what is left is not very soluble. With plentiful rain there is almost always lots of plant growth, so the rain may not fall on actual soil at all, but falls on a deep bed of fallen leaves. This water is soft. It has very few minerals. Low GH and KH. The pH is usually low (acidic) because of the decomposing leaves.

If the rain is sparse, then when it does fall, it may land on rock that has not been dissolved over time, so more of that rock dissolves with each rainfall. Also in areas with sparse rain there are not so many plants, so the rain is more likely to fall on the rocks and soil. If these rocks and soil are high in the various carbonates such as calcium and magnesium carbonates, then the run off water becomes rich in these minerals. It has high GH and KH, and almost always high pH.

Now, the importance to aquarium keeping:
Fish live in balance with their environment.
When there are not many minerals (of any sort) in the water the water keeps entering the fish cells through the gills and digestive tract. Too much water enters, so the fish needs to get rid of it. Fish from soft water are very good at getting rid of the excess water, and at retaining the minerals they need from that water, even when the minerals are there in very small amounts. These are soft water fish. Mostly they thrive in water with low GH and KH, usually acidic water. (The pH is less important). Some species are so good at trapping minerals they can die when they are in hard water, the minerals build up in their system faster than they can use them.

Fish from hard water also have some water entering their cells, but a lot less, so their bodies are not very efficient at getting rid of excess water. If they are placed in water that is too soft they can swell with a condition called Dropsy. (There are other things that can lead to dropsy, but the inability to get rid of excess water is the basic problem). These fish thrive in water with high GH and high KH, and almost always water with high KH also has high pH.

However: GH, KH and pH are separate things, though there may be some trends where one test result is similar to the other. Measure them with separate kits. They each mean something different in the aquarium.
Diana is offline  
post #7 of 7 (permalink) Old 05-10-2012, 10:45 AM
Planted Tank Guru
 
wkndracer's Avatar
 
PTrader: (68/100%)
Join Date: Mar 2009
Location: Citrus County,Florida
Posts: 6,186
Re post #6
KH is not potassium. K, the chemical symbol for potassium, is from Kalium, a Latin word.
Potassium bicarbonate (potassium hydrogen carbonate), KHCO3 is not a mineral value that registers as KH?
KH can be potassium based eliminating the additional sodium component of NaHCO3 or the (GH) component of most calcium based buffers.
Once you have the right GH in the tank, make the KH pretty much similar, within a couple of degrees.
Why? keeping soft water species and wanting a reduced pH value is why this topic comes up most often. Why would you increase buffer values beyond what's required for basic pH stability? Doing so only adds to TDS and water hardness.

Without being as nicely wrapped in explanations (no cheese in mine LOL) most relevant points to the OP's question (and information errors) were addressed in my post.
We could also add that <6.0pH, truly acidic conditions (not injected CO2 induced) not only effects ammonia formulations but also hinders bacteria growth (some of which is important to tanking). 5.5pH maintained eliminates almost all bacteria.

(imo) Well thought / written reply Diana

(don't trust Wikipedia and web forums LMAO!) without verifying information.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

If at first you don't succeed,,, keep kicking it
RubberSideDownOnTheLanding,
2-75g planted, 3-55g planted, 110g w/30g sump, 2018 update returning to sanity (Nutz)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
wkndracer is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome