I have a 20 gallon long aquarium dedicated to snails of different species. I have it filled with a mixture of nirite, mystery, chopstick, pagoda, black devil, assassin, ramshorn, bladder, pond and trapdoor snails. This last week, I had a bunch of babies hatch out and that's when all the issues started. I lost about 7 adult mystery snails and an orange footed rabbit snail. When the babies hatched out it caused the ph to drop a bit, so I fixed it with a buffer. However, most of my adults have passed away and the others in there are sick. The japanese trapdoor snails seem to be a bit sick as well. I have done large water changes, triple checked all water parameters and everything is perfect! Could the ph drop for just one week do this much damage?