Just a question first, why were you mixing 4 tbs of Tiger Bloom per gallon of water? The directions say 2 teaspoons per gallon of water which is 6 times less than what you were feeding them with. What was the ph of your water after you added that much Tiger Bloom to it? Was it between 6.2 and 6.5? You may have dropped the ph below 6.2 by adding so much Tiger Bloom.