Planted Tank Guru
Join Date: Dec 2004
Location: Skagit County, Washington State
You can always put some crushed coral in the can to keep the KH replenished. Because I imagine you already know pushing in that much CO2 will deplete it and one should play it safe. If it gets near 3, I get nervous. KH of 4 is not really high, more like ideal IMO. I have 6.4 pH standing water out of a tap, and add 1.5 to 2 teaspoons of baking soda to 50G to bring the KH up to near 3. My CO2 brings the pH right back down to 6.7 pH, but the crushed coral keeps a moderate 4-5 KH for me. I have to add cal.chloride and mg as both my KH and GH are near zero out of my well water's tap.
Three Tanks...Eheim 2128 & XP3-90G, Eheim 2128-65G, Eheim 2232-25G.... Tek 4x54 watt T5-90G, Aqualight 96watt PC 65G low tech, 65 watt Aqualight-25G.... Hydors-90G & 65G ... Flourite in 90, 65, & 25 Gallons, .... Auto Water Change/Auto dosing on 90 & 65 gallon..... AGA member......