Question about Equilibrium and sick fish
My tap water is very soft around 1-2 gh 0-1 kh. I see it recommended that GH in in planted tank should be 3+ for healthy plants. This ends up requiring that I raise the GH of my tank about 2 degrees+ whenever I change water in my tank.
The measurement to raise 20 gallons 3 degrees its 1 table spoon.
For a 50% water change on a 20 gallon I add about 3/4 tsp to raise it about 1.5 degrees. It doesn't happen every water change, but it seems like over the course of 1-2 years I will usually have fish that develop some issues from water parameters fluctuating. I'm not sure if its because I'm not changing exactly 50% or something else. It doesn't seem like the water possibly changing .5-1 degree would be a lot, but they're nano fish (CPDs). It doesn't seem to affect my pygmy cories / shrimp / guppies.
I have no water quality issues. My ammonia, nitrite are always 0 and nitrates stay below 10.