https://www.theaquariumwiki.com/w/api.php?action=feedcontributions&user=PraXis&feedformat=atomThe Aquarium Wiki - User contributions [en]2024-03-28T19:11:05ZUser contributionsMediaWiki 1.29.2https://www.theaquariumwiki.com/w/index.php?title=General_Hardness&diff=82721General Hardness2016-04-28T12:39:09Z<p>PraXis: </p>
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<div>== °GH - General Hardness ==<br />
General, total or permanent hardness is a measure of the overall concentration of [[calcium]], [[magnesium]] and other ions. It's measured in degrees, with one degree equal to about ''17.9mg/l (17.86mg/l)''. The degree symbol is often replaced with a "[[d]]" (i.e. 6dGH or just 6dH). The harder the water, the higher the GH number.<br />
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*Some countries measure GH in [[ppm]] (like the USA), others use the German unit dH.<br />
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*Some countries use 'GCH' (General Carbonate Hardness) instead of 'GH'.<br />
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*Some retailers (ADA) use TH abreviation (Total Hardness)<br />
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{| border="1" class="wikitable" style="text-align:center"<br />
|+ Levels of Hardness<br />
! Degrees !! Parts Per Million || Description<br />
|-<br />
! 0 - 4 dH<br />
| 0 - 70 ppm || very soft<br />
|-<br />
! 4 - 8 dH<br />
| 70 - 140 ppm || soft<br />
|-<br />
! 8 - 12 dH<br />
| 140 - 210 ppm || medium hard<br />
|-<br />
! 12 - 18 dH<br />
|210 - 320 ppm || fairly hard<br />
|-<br />
! 18 - 30 dH<br />
|320 - 530 ppm || hard<br />
|-<br />
! Higher <br />
| > 530ppm || Liquid rock (Lake Malawi and Los Angeles, CA)<br />
|}<br />
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==Raising GH==<br />
If you live in an area with low GH water you may need to add chemicals to increase the GH level to a level suitable for your aquatic animals.<br />
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*[[Calcium carbonate]] (CaCO3) is a typical and cheap material to do this. You can find it as Coral sand, coral pieces, sea shells, Cuttle-bone pieces, etc. It is also sold in gardening shops as 'Lime' usually in a powder form. It will however raise [[KH]] as well as GH. Which is probably a good thing if you live in a soft water area.<br />
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*[[Magnesium sulphate]] (MgSO4) or more commoningly known as Epsom salt. This will raise GH without altering [[KH]]. Used in a ratio of 1:3 with CaSO4 ([[Calcium sulphate]]) (1 part MgSO4 to 3 parts CaSO4) to make your own GH mix for a freshwater aquarium.<br />
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== Links ==<br />
*See [http://www.thekrib.com/Plants/CO2/hardness-larryfrank.html The Krib] for more on this.<br />
*[http://web.archive.org/web/20060116204426/http://www.marineland.com/science/articles/9hardness.asp Hardness: A Term with Many Meanings]<br />
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*[http://www.aquaticplantcentral.com/forumapc/el-natural/29062-calcium-dosing-procedure.html How to raise GH without raising pH]<br />
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[[Category:Glossary]]</div>PraXis