i have soft water and a 6.5 ph to 6.9 ph in my 10 gallon planted tank. it is a dirted tank that is capped with fluorite. my lugwia and amazons are doing great but my sage and vals dont seem to grow very tall or spreed out. i also have medium light and i dose ferts. what is wrong . i heard that gh has something to do with it. i heard that valls and sage like harder watter. is this ture.