Hi everyone, I need some solid advice for my 70 Gallon tank. I have had it cycled and running for about 8 months. We have 1 rainbow shark and 2 Bala sharks (we plan to get a bigger tank). We have had other fish months ago, but being a beginner I did not know everything about the cycling. The tank has been fine until yesterday when I took my water to get tested at the pet store. They said it was high in ammonia...on the verge he said of being dangerous to the fish. The PH was high also. I asked what it read and he repeated the same thing to me. I believe it is from allowing my kids feed them(my fault). I was advised to get Bio-boost and feed once a day. I got it and put it in when we got home. They seemed very calm, then this morning the Balas were hovering at the bottom not wanting to swim and the Rainbow was being aggressive to get them away from him area. I went ahead and did a 25% water change and cleaned out the filter. I did not add my complete water conditioner b/c I read that someone had a bad experience when they had both chemicals in. The balas are swimming more but doing an odd mouth thing like they are not getting enough oxygen from the water. I have a aerator and a Cascade 300 filter. We also have a heater that keeps the water at 79 degrees. I am not sure what exactly to do. It seemed the fish had a bad reaction to the Bio-boost. If I lower the PH will the lower the ammonia? But also the PH is not much above what the sharks need...ANY HELP PLEASE!!