Originally Posted by t.ropical m.ist
i was told by someone who has had fish for years and breeds many different kinds that this was no problem. my neons color is actually really, really bright compared to the way they were in the store, too...
This person who coached you, did they also explain to you about the nitrogen cycle and overstocking a tank from the beginning, before the tank is cycled? Did they also teach about fish that are prone to illness/death from water quality changes such as will happen during the cycle?
I think what you were told was either misquoted to you or you misunderstood. Can you keep all of those fish in a 10 gallon tank together long term? No. There simply is no way to make that work, and not just because of water quality issues, but because of space and territory. If you are prepared for and intending to do 90% water changes daily, you could beat the water quality issue, (water would have to be properly prepared for this to work) but then the fish will all grow to their full size quick enough to cause issues with space and oxygen levels. Extra aeration levels can be artifically added with air stones and filtration, but you will still be left with territory and space problems. No matter how you look at it, 10 gallons just isn't big enough for the fish you have in there now.
The reason we have told you to expect death if you don't return some of those fish asap, is because neons, corys, and the sparkling gouramis, and the guppys, are all sensitive to ammonia and nitrite. With more than the maximum amount of waste in a tank that has no bacteria culture to break it down yet, those levels are going to get extremely high, and the heavier the waste level, the longer it will take for enough bacteria to build up to consume ALL of the waste, meaning that when the culture begins breaking down ammonia, you will then get nitrite, but you will still have a high ammonia level to go with it. If ammonia or nitrite doesn't kill them by itself due to the high spikes, then the combination of the 2 together will surely do it.
Now, lets take into account how large each of these fish will get to be, and rather quickly if they live...
neon tetras average about 1 - 1 1/2 inches each
fancy guppies average up to 2 1/2 inches each for females, and slighly smaller for males
sparkling gouramis average about 3 - 4 inches each
glowlight tetras average 1 1/2 - 2 inches each
cory cats average 3 inches each, and over 1 inch tall/around
Take some paper and measure these out and cut a "fish" in each size range for each of your fish in the tank. Lay these cut outs next to your tank, THEN tell us where you intend for these fish to go?
How often are you feeding these fish and how much each time? What kind of food? What kind of filter are you running? Are there live plants in the tank? How much decoration is in there?
Can you post a picture of the tank for us?
The best thing you could do right now would be to return all but the glowlight tetras. Let the tank cycle properly and easily, those fish could handle that much. Then, if a few weeks, after cycling is safely complete, add a few more small fish like the neons OR the guppys. Wait another 2 wks to let the tank adapt to the new waste levels, and for the fish to settle in, then add 1 cory cat, and call it a full tank. In the mean time, watch your water quality with water testing, and add as much decoration to the tank as you can to provide "safe places" for the fish to get away from each other, and territories they can all claim. The cory cat will need some kind of cave... the neons and glowlights, and guppys will need things like rock structures and plants mid to upper range in the tank.
In the mean time, keep your feedings light... only what they can FINISH in 1 minute, once, every OTHER day, and daily water changes of 20%, and call your LFS and see if they will allow you to return everything but the glowlights.