I have a 72 g planted tank, (although with few plants). I fertilize with Flourish Excel, Flourish, and Equilibrium. I've also recently moved and done a substrate change from standard gravel to Eco-Complete planted aquarium substrate. I keep 3 clown loaches, 2 blue botias (red-finned loach), 3 Blue Acaras (cichilid family), 2 Sumatra two spot catfish, 5 Black Veil Angels, 2 Plecos, and 1 Royal Danio (blue-hill spotted trout).
I'm writing because I recently moved about 40 minutes away and my tap water is much harder than my fish are accustomed to. The tap water values are as follows:
KH 8 degrees (143.2)
GH 7 degrees (125.3)
My former location tap water:
KH 4 degrees
GH 5 degrees
My current tank water readings:
KH 9 degrees (161.1)
GH 12 degrees (214.8)
Prior to the move, I was able to keep my PH easily at 7.0. When I did my most recent water change I treated the water with Seachem Acid Buffer and Seachem Neutral Regulator. This led to a PH swing down to 6.8 which the next day rose to 7.4. HUGE swings! I don't want to keep having to buffer the water at every water change, as I know that these drastic changes in PH are super dangerous to my fish, and the buffering effects don't seem to last. I've also recently (yesterday) added a large piece of driftwood and two smaller pieces of driftwood.
My questions are:
1. I've never kept fish at such a high PH (8.3) so I do feel the need to buffer the water. And - my fish all prefer a lower PH range of 6.5-7.0. Can they adapt to such a higher PH?
2. Any thoughts or ideas of why my tank GH and KH readings would be higher than the tap? I'm new to plants, could it be because of the Equilibrium I dose or other plant fertilizers? I tested my aquarium rock with white vinegar and there was no reaction, so I'm guessing it can't be from that. Perhaps the substrate?