Raising gh without raising ph - The Planted Tank Forum
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 05-31-2020, 02:28 AM Thread Starter
Planted Tank Obsessed
butchblack's Avatar
PTrader: (0/0%)
Join Date: Oct 2019
Location: Waltham, Massachusetts, USA
Posts: 334
Raising gh without raising ph

My tap water recently jumped from ph7.4 to ph 8.8+. I found out that swordtails like harder water, so unlike my other two tanks I'm not lowering the ph as much. However, the tap kh is still low, 40ppm. I'd like to raise the gh+kh a bit, would adding a bit of crushed shell in the HOB filter help?

The real fountain of youth is being a musician
butchblack is offline  
Sponsored Links
post #2 of 3 (permalink) Old 05-31-2020, 03:28 AM
Planted Tank Guru
Seattle_Aquarist's Avatar
PTrader: (65/100%)
Join Date: Jun 2008
Location: Seattle, WA
Posts: 6,641
Hi @butchblack,

Adding cuttlebone to the filter media will increase the calcium carbonate resulting in an increase of calcium (and dGH) along with the pH. Adding Seachem Equilibrium increases the dGH with minimal change to pH since it contains no carbonates. Hope this helps!

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

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

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

75 Gallon, 2X55W AH Supply CF 8800K, 1X 59W Fluval Plant (3.0); 45 Gallon Tall, 1X 46W Fluval Plant (3.0); 30 Gallon Long; Fluval F&P 2.0; 20 Gallon, 1X26W AH Supply LED; all with CO2 & (Calcined) Montmorillonite Clay
Seattle_Aquarist is offline  
post #3 of 3 (permalink) Old 05-31-2020, 09:02 AM
Planted Tank Guru
DaveKS's Avatar
PTrader: (0/0%)
Join Date: Apr 2019
Location: 67212
Posts: 2,297
Seachem Equilibrium doesn’t add to PH/KH directly on dissolution but let the carbonic acid in water work on those minerals for a few days and it will slowly feed your carbonate system. How much that will effect your PH depends on how much and how often you dose GH side. Add it all at once on water change and you’ll probably see a slight PH rise across 2-3days. Add it a little on water change day and then a little on top offs (1-2x wk) for evaporation throughout week and there will be very little PH shift.

Remember your GH test kit only reads Ca/Mg. Equilibrium is mostly potassium and that will never show on your GH test kit.

Guaranteed Analysis
Amounts per 1 g
Soluble Potash (K2O) 23.0%
Calcium (Ca) 8.06%
Magnesium (Mg) 2.41%
Iron (Fe) 0.11%
Manganese (Mn) 0.06%

Elemental potassium is present at a concentration of 195,000 ppm (19.5%). Fertilizer laws require us to list potassium in terms of equivalence to a material that is not present (K2O) rather than the more scientifically sound method of simple elemental equivalence.

Derived from: potassium sulfate, calcium sulfate, magnesium sulfate, ferric sulfate, manganese sulfate.

The potassium, calcium and Mg sulfate (Mg Sulfate=Epsom Salts) shown above are easy to buy as raw salts and build your own dosing solution cheaply. Add some potassium bicarbonate and sodium bicarbonate (baking soda) to your salts selection if you want, they’ll only show up on your KK/PH tests. If you dose some potassium bicarb lower your potassium sulfate dose, they are both adding K, just in different chemical compositions.
DaveKS is online now  


Quick Reply

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


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

Email Address:


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