Well Janis, the morning came and to my amazement....no fish losses. After the drastic changes yesterday, I fully expected to find several dead this morning. I won't make a habit of such drastic changes (really hard on the fish) but in my case...it was the only option. Angels were alert and had regained their color. Even the Discus which are the size of a dime were doing just fine. I meet with Joe today and I am to bring him several water samples (one from the tank, one from my storage barrel, one from my tap). I do have to admit, I see the water as clearer...polished even. Joe recommends dumping all filter media weekly, especially charcoal. That can get expensive and rather hard on pump housings. I have an old magnum 350 which I can use as a scrubber, and remove the charcoal from my other pumps. I can use the scrubber weekly by just tossing the input and output over the side and fun for 4 hours. Kind of like dialysis patients do, and at the end discard. Will ask him about it this evening. According to Joe, the aquarium filter system is like a large kidney. I would be performing dialysis on the tank 1 to 2 times per week. So you know me...I started researching dialysis like my life depended on it. Thanks for the advice about painting the back of the other tank black. Not sure which paint to use, but I am looking at a a water based black. It gives depth. One vertical coat followed by one horizontal coat should do the trick....talk to you later.......Dwayne