Shannon I know exaclty what you are going through. I went through the same thing when I got my first tank. Everytime I did a water change, I lost fish. It may seem like a hassle but you may want to take your fish out of the tank when you change the water. We do that because we have a gravel vac that looks up to the garden hose (it won't fit on the kitchen sink faucet) and we run the water straight from the hose into the tank and it isn't conditioned yet and plus it tends to be quite a bit colder.
If I were you, now remember, this is just my opinion, purchase a couple 5 gal
buckets from Wal-Mart. Mix your water with the conditioner (we use a pH 7.0 conditioner), let it sit overnight (somewhere were it doesn't get too cold), and the next day take out your fish and do a partial water change using the water that was previously mixed. We did this for all of our smaller tanks until we purchased the 55 (too many buckets). We haven't lost a fish yet since we started doing this. It can be a hassle but now we are confident that we won't lose anymore fish.
The brown stuff on your plants is normal. You may want to purchase a baby pleco. Now when I say baby I mean a small one. This will help control the algae. I have been told not to clean my plants at each water change because you will lose too much bacteria but we do anyways and our fish have not suffered. The pleco won't get rid of the brown entirely, but it will help. I recommend getting a very small one because I went to the lfs
last week and they had two HUGE pleco's in their tank. By purchasing a small one you can have him for a longer period of time.
- Welcome to AA! This was just my opinion.