3-5dGH is enough for good growth with most plants and values do not need to be matched in ratio GH/KH LOL.
I figured as much, but like I said, when I was researching I found a couple of sites that recommended matching them. They never gave a reason though, so I don't know why. Since the GH booster raises in 3's per tablespoon, I'll just aim for 6dH.
Are you sure your gh test kit is working correctly?
I believe it is. Back when I was using test strips they told me that I had a high alkalinity, but like no general hardness. I bought the API test kit and it gave me the same results. I've lived in places with both hard and soft water, and the water here definitely "felt" soft, so to be honest I was surprised the KH was as high as it was. I did test the KH against some 4dKH solution and it matched up. I haven't checked the GH bottle yet though...I think Hoppy has a way to calibrate it on here, I'll do that the next time I have some free time just to confirm, although I do think the results I have are at least close to true.
I have come across a few posts on the internet where someone was in the same situation as I am. It's definitely an unusual combination though. I've wondered how it comes to be...I'm assuming the water is naturally soft, but the water company is adding something to raise the KH.
Does anyone have any opinions on whether or not I'll need to dose additional potassium? It is a 40 gallon tank, and I do 50% water changes a week. So if I add 2 tablespoons of GH booster a week to get to a GH of 6, how much potassium am I adding? Would I need to add more? I know it is difficult to OD on K, but I don't want to add more than I'm taking out and end up with a dead tank in a couple months.