Good morning, I have a 56 gallon planted tank with angelfish, gourami's, black neon's, madagascar rainbows. last night at around 6:30 I did a 50% WC in my tank as I was adding two new plants to it, before I did the wc my ph was at 7. This morning at 10am. I checked the PH at its at 6. my results as of this morning are High PH 7.4, Ammonia-0, Nitrite-0, Nitrate-0 and temp-80. I use prime for all my wc. Will this be a problem for my angelfish. I'm a little nervous because during the WC a angelfish died. Thanks for your help.