Raising KH with Baking Soda
My parameters are PH 6.6, GH 3, KH 0/undetectable (first drop is yellow). I did a little bit of research and put almost 1 teaspoon of baking soda mixed with water in my cycling (which i'm having some issues with) 40 gallon. It raised the PH to somewhere around 6.8-7.0, GH 3, KH 4. I only need it around KH 2 since I just want my PH to stay stable even though i've never seen it drop; just want to take precautions.
My question is, is it safe to do this long term to ensure there is some buffering capability in my water? If so, should I try to keep it at the same number all the time? Example would be if day 1 I add enough to get to KH 2, 2 days later it dropped to 0 or 1 KH again, would I add more baking soda to make up for it or wait until end of the week water change?
If not, what would be a good product to use for just KH? (although baking soda is pretty cheap!) I don't have access to crushed coral and ordering online would make for hefty shipping fees.