i tested my water today (with lights on)and my PH dropped quite a bit. two days ago it was 8.2 now it is 7.8.
How long had the lights been on? And what time was the ph
checked before? To get an honest feeling of whether your ph
is dropping, you need to check it at the same time every day, best time is in the latter half of the light cycle. It will be lower during the first half.
40 lb of LR
could certainly depress the ph
a bit, there is bound to be a little die off and the biological processes to clean that up will produce acid and co2
I wouldn't bother with the buffer, just do a healthy water change and keep your eye on that ammonia and nitrite.