KH and soft water species (tonina and Syngonanthus)

[mythin]

I have had my tank set up for a while with seiryu stones which shot my KH up to 12ish, but Ive done several water changes with RO and now my KH is down to about 4, ph 6.5, substrate is similar to amazonia (brightwell's rio escuro), I dont think my substrate can buffer any lower anymore, maybe the seiryu used up all its buffering capabilities?

Either way I was wondering if anyone had kept tonina or Syngonanthus "Uaupes" in KH anywhere close to 4, or does it absolutely require 0-1 kh?

[Tom Barr]

Plenty have kept them at that KH range. I'd remove the stones before I went through all that trouble, there are many types of stone available that do not mess with things.

[mythin]

Yes, the stones have been sold last week, after which is when i went through my RO water swap spree, Houston tap water is really hard, so I think im just going to keep doing water changes with pure RO. Have you grown Syngonanthus "Uaupes" before?

[Tom Barr]

Yes, it was a little troublesome to acclimate, but did fine.

Houston Tap stinks.