Originally Posted by rg0p
As for adaptability, it does say so in the plant profiles here in this site. And it seems from some posts here people have had some success with soft water. However, I do agree that seems to be main issue here. The reason I am hesitant to adding some chemical to raise the hardness is that I want my cardinals happy in there, As such they are sensitive/delicate fish, mostly..... May be I can add some crushed corals in canister? Or may some epsom salt while PWC? Nothing else, I will just the val stay as is, as along as it's not rotting......
Thanks again for all the help :)
As I mentioned previously, this is a case where (in my view) the fish must come first. I do not raise my GH above 5 or 6 dGH, depending upon the tank, as I have a number of wild caught soft water fish like (and including) cardinals. A scientific study found they were OK in water with a GH of 4, but above this they became susceptible to "hard water" issues like calcium blockage of the kidneys, leading to premature death. The higher the GH, the worse the blockages and sooner death.
I have near-zero GH out of the tap, which is superb for my fish, but I can't keep plants alive with so little calcium/magnesium, so I use Equilibrium from Seachem to add these. But I do not go above 5 or 6 dGH. But having tried Vallisneria, and had it basically fail, that's it; I am not going to jeopardize the fish just to have one plant when there are so many others.
Crushed coral will add calcium, but it also raises the pH sky-high. I have tried this; as little as half a cup in the filter of my 115g tank raised the GH by 1 but sent the pH from 6 up to 7.6. Not a solution obviously. Epsom salt, which is magnesium sulfate, will also raise the GH, but this is only via magnesium; the calcium is completely lacking. And when I tried this in one tank, the excess of magnesium resulted in the swords developing holes; there was obviously a chain reaction with other nutrients.
If I had a GH of 4 out of the tap, I would be in heaven. Equilibrium is not inexpensive.