Planted Tank Guru
Join Date: Dec 2004
Location: Skagit County, Washington State
CAN K2S04 increase dGH??
[B]My water chemistry is all self taught... Tonight I was re-reading Baench's Aq. Atlas and found a part that mentioned potassium raising total hardness. I ask this question because, after a major screw up on my new 90 gallon tank, I finally got my water down to 8dGH with a couple of 50% water changes. My tap/well water is near zero GH.
Because I haven't dosed k in this tank except with KNO3 and KH2PO4, I put just under 1 teaspoon of K2S04 into 30 gallons of change water. My GH raised upto about 10dGH (or 11 on a second test) on tonight's reading after this morning's change. The last time I tested for GH was after the two big water changes about a week ago, before any dosing on KNO3 and KH2PO4. Also, I should mention that I have dosed about 10ml of KH2PO4 and just under a teaspoon of KNO3 a couple of times this week, prior to this last change. The nitrates were rising to about 20ppm after dosing but going down to 5 to 7 ppm before redosing on each odd day.
I want to get back to a nice 4 to 6dGH. Should I stop with the potassium sulphate altogether and just let the potassium in the KNO3 and KPO4 do the job? Perhaps I'm getting too much K in there and its causing the water to get too hard? Is this a possibility? Or is this dGH not that big of deal to the plants, anyhow. The KH is at 5 ish and pH about 6.8 now. Thanks for your help! bob
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