ppm dGh dKh Going mad.....

[steve b]

Hi All, been doing too much reading and got totally confused.

If I have a TDS of 400 ppm this equates to 22.35 dGh, is there a formula that will tell me what the dKh is? or just test with a Kh test kit? Need to know the buffering capacity.

Does anyone just measure TDS and not dGh/dkh?

[Vanman]

I am lazy and measure TDS and ph. That is if I measure anything. I just do 2/3 water changes twice a day. I only have two tanks with fish so this is easy as both are drilled with valves to drain them. I also have fill lines plumbed to each tank. My water is very soft, 20 PPM TDS, and acidic. I run it through a calcite filter to protect my water heater. The water for the fish goes through the calcite filter. I used to have a geothermal heat pump that heated my hot water and had to have the calcite filter to protect the heat exchanger. If I ever get a large water aging tank the fish will get straight well water.

[For100]

Hi All, been doing too much reading and got totally confused.

If I have a TDS of 400 ppm this equates to 22.35 dGh, is there a formula that will tell me what the dKh is? or just test with a Kh test kit? Need to know the buffering capacity.

Does anyone just measure TDS and not dGh/dkh?

Hi Steve,

This is a complex question… TDS measures Total Dissolved Solids, but dKh (carbonate hardness) and dGh (General hardness) dont have a linear relationship to TDS. You can have many other cations or anions disolved in the water (for example nitrates or phosphates). This will increase your TDS without having any impact in dGh or dKh. If you want to measure hardness, there are several test kits to measure dKh or dGh in the market.

Just wondering why are you concerned about buffer capacity, are you planning to use RO filters?

If you would like to read more, you can find a ton of info in this link below:

https://www.2hraquarist.com/blogs/ph-kh-gh-tds

Hope this helps

[steve b]

Thanks, yes using RO/DI just seen many people use TDS...ppm to measure Gh for water changes but never seen anyone say what their Kh is for stable Ph using ppm

[Second Hand Pat]

Thanks, yes using RO/DI just seen many people use TDS...ppm to measure Gh for water changes but never seen anyone say what their Kh is for stable Ph using ppm

Hi Steve, you can measure GH and KH separately. See if this helps https://www.amazon.com/Aquarium-Pharmaceuticals-Freshwater-hardness-Test/dp/B015MBREV4/ref=sr_1_6?crid=1RYCQASJP2ZTQ&dib=eyJ2IjoiMSJ9.iC4llD4l5OiPU62OoX1pcjOGV7jIiddyE hV4XcZtulQhwSedHdalj-aVL_0Zk0IhkiioYblaPgKprLeoV6VxHKzVo74gCmDddZwXQm9r GJoblFAU5vHZU4-Bw-rHWjAPO1nwt_xOHW0A7GlI2FyP0osLoJJsE932qhHaIHUuGtgr l0cIhiatGY4ebp7DD8DqibZcCHrQxANRBIEKSN-NG_1TwHhwa4UInyHiAMkSC-XIdCKg1Kife7MJsG8CM9hHp4-sxgS0hA_iESeGkV_L41CLKNxKS0gsoYZBBRV2jDA.k_MGp6QJx JzkVx7MRPj6MNXHdOWlHfrd0UG59_apDmo&dib_tag=se&keywords=api+test+kit+kh&qid=1709207846&sprefix=API+test+ki%3D%2Caps%2C343&sr=8-6
Pat