I've had about 4 fish die within the last month or so and I dont have any affordable fish stores in my area to buy testing strips or anything. It all seemed to start when I added a new plant in the water. Water sprite i believe it was. It ended up dying. I have 2 pieces of medium/large driftwood in there as well, so the water does have tannins.. and i read that can lower the PH? I have a pregnant fish in this tank right now and Im worried that she and her fry will die so please reply asap... Its a 30 gal aquarium and I have 7 swimmers, 1 pleco and 1 catfish so I dont see it being ammonia poisoning. Please help!