fish death.

Question
First of all try to bear with me, I'm on mobile web. I really hope somebody can help me being I've asked everybody.. I never knew I even liked fish but my sister gave me a 30 gallon tank, and I went to a pet store and every couple weeks I bought more fish. This soon became a hobby, I would lay down and watch them swim, I was entertained.. anyway they were so pretty and seemed to be healthy. I bought everything my freshwater cold water goldfishies needed, filter, water conditioner, thermometer, etc. I always consulted petstore employees before making changes to my fish tank, and I took care of them. It all went downhill after I changed their substrate from pebbles to sand..now I was informed as long as I cleaned this playsand well and rinsed it untill the water drained clear, didn't have it more than an inch deep, cleaned the surface of it with a vacuum, all would be well. I thought they enjoyed it, they rolled in it constantly, and stayed near the bottom of the tank. It was another day or two I notice my most recent fish died. He was an algae fish, pleco. I had 3black moors, 4baby goldfish, 2goldfish, and 2pleco algae eating fish. The next morning, the other algae went, and I was very concerned and soon distressed. I cleaned my tank immiediatly, 30 percent water change, and inspected the other fish for signs of an infection...I thought the white dots on there body's were sand, but death struck again, my black moor was a goner.. This seriously made me panic. I went to walmart and bought some lifesaver medication, because it listed everything my fish had before he passed, clamped fins, peeling body, blood spots, tail rot, it was awful. I treated my tank, and its day two of 5. I'm so sad right now being my remaining fish have signs the others did, and I know they're suffering, and I hate feeling like maybe its something I'm doing or have done wrong. They seem to loose bouyancy before they die, but they can still move their eyes and mouths. Its absolutely horribly sad to watch, feeling as if I could save them if I wasn't so ignornant in fish knowledge..please help me. Will this medication have any effect? Would I be better off flushing them being they are all bleeding and are in pain and misery? Or should I wait it out? Though I never really cared for fish, its knowing pain is understood in all languages and species..  

Answer
Hello Kristina, I first have to ask you hold long you have had the tank up and running, before you added the fish to it. This is because sometimes adding fish to your tank immediately and quickly can pose a potential threat to your fish's lives. This is based on many factors, such as the water chemistry. You must always and often monitor levels of Nitrate, Nitrite, Hardness, Alkalinity, Ph levels and chlorine levels(when adding water),and also ammonia levels. Nitrite Ammonia and ph levels are the most critical to the well being of your water quality and ultimately the life of the fish. You say you had 2 pleco in the tank, a 30 gallon tank. Is this because there was an algae problem? You mentioned the fish rolled in the sand, are you sure they weren't trying to "scratch" and things like they do when they have ick? It sounds like this is what they had being that you mentioned seeing white spots all over them. Any disease and stress of whatever kind, can literally "drain" the life right out of any fish. Stress is bad, in any form. It makes them more susceptible to diseases infections and parasites as they lose vital nutrients which help them fight that stuff off. Your fish could also have the dreaded "new tank syndrome" , which is why I asked about the establishment of the tank. If you didn't or don't monitor water quality, I highly recommend you go get testing supplies to check for the things I mentioned above, Nitrite, Nitrate, etc. Some symptoms of certain illnesses mimic the symptoms fish display when water quality is poor but ultimately share the same consequences. I would recommend to anyone with a fish tank to have a "hospital tank" for problems like this, that way if a fish is acting sickly, you can remove it from the rest of the bunch and treat it separate from the rest of the community. All in all, you are the one who has to make the final judgement as I am not physically able to see the state the fish are in, If you feel that they are to too far gone, and sick, by all means, I would put them out of their misery. Seems more humane than letting them suffer if you ask me, but thats just a personal opinion. If you have any more questions, comments or concerns, please keep in touch. If you need more information about the levels of water quality, I'll be more than happy to continue to help you in any way. Good luck. Keep me updated.