Balancing pH, KH, plant and fish requirements
My first post, because I am having trouble finding specific advice for my situation.
I've an old 55gal. tank that I've had for years and am rejuvenating to make another attempt at a heavily planted aquarium. The problem is my (well) water parameters: the GH appears tolerable, c.70-80ppm; but pH is steady at 8.4, and the KH doesn't budge from c.220ppm.
Because most plants I've seen seem to require pH no more than 7.5 and KH up to 8, I added a new large piece of driftwood, and peat moss to one of the filters. It's only been a day so the pH hasn't changed, but the KH dropped to about 180-200ppm. I assume everything will drop a bit more and stabilize but don't have great hopes.
So, my questions: from most of what I've read here and elsewhere I assume that most fish can adapt, and it's best not to mess with the balance too much. My only survivors (one 10-12 year old Silver Hatchet and one same-aged Cory) have prospered. So, would a slow, "gentle" transfer of new fish into such a semi-drastic environment hurt them? I am well off the beaten path so it takes some time to get from a store (not to mention shipping them). Are softwater species like tetras more vulnerable?
And what are the consequences for plants? Are they as adaptable as the fish? If as I've read they can have a small impact on KH, will that compensate enough? I do not know what might have doomed our previous attempt at live plants- perhaps lighting, but if KH might've had an impact, do I have any recourse, or am I doomed to plastic?