Aquatic Plant Central - View Single Post - [Wet Thumb Forum]-Calcium dosing to increase GH

colinsk · 04-14-2009, 10:13 AM

Any slight addition of H+ in the water will make large pH swings unless you have some kH (alkalinity, carbonates, CO3, for this discussion we can consider them the same). An RO unit removes almost all of the kH. Normal biological processes tend to want to swing the pH lower and having some CO3 as a buffer is a good idea to keep your tank from swinging pH. In a few hours you could go from 6 to 5 pH. I prefer to run around 7 and have both fast and slow buffers in the tank. I use CaCO3 as a fast buffer (from my tapwater) and oyster shells as a slow buffer. This gives me time to notice a problem before it is a big problem. I still keep my kH fairly low at 4 but it is much better than 0.

04-14-2009, 10:13 AM	#48 (permalink)
colinsk Member Join Date: Dec 2008 Posts: 99 iTrader Ratings: 0 Plant Points: 6350	Re: [Wet Thumb Forum]-Calcium dosing to increase GH Any slight addition of H+ in the water will make large pH swings unless you have some kH (alkalinity, carbonates, CO3, for this discussion we can consider them the same). An RO unit removes almost all of the kH. Normal biological processes tend to want to swing the pH lower and having some CO3 as a buffer is a good idea to keep your tank from swinging pH. In a few hours you could go from 6 to 5 pH. I prefer to run around 7 and have both fast and slow buffers in the tank. I use CaCO3 as a fast buffer (from my tapwater) and oyster shells as a slow buffer. This gives me time to notice a problem before it is a big problem. I still keep my kH fairly low at 4 but it is much better than 0.