I have a feeling that if you could infuse your water with a high tannin content, using peat, almond, or other leaves, you might have a chance. Because that species natural waters have a high tannin content, which is unsuitable for certain pathogenic bacteria to survive. This may be a bigger problem than pH alone, becaus high pH, and conductivity are the soup of choice for bacteria such as HITH, and other maladies S Americans cichlids of that area seem very prone to.
I believe this is the reason we see so many oscars with HITH, although not as acute for them as the Uaru, the lack of tannin along with high pH acts as to caue chronic maladies over time.