If you take Mikey's idea and start over make sure you cycle your tank before you put fish in. It takes a couple of weeks. Maybe shorter if you get some good established beneficial bacteria. Here is a step by step on how to cycle:
Every new tank, with new filtration, has to be cycled to be safe for aquatic life. What is meant by "cycled"?
"Cycled" is a reference to the Nitrogen cycle. This is the bio filtration that happens in our filters.
In short,
"Ammonia" (toxic fish waste) is converted by bacteria into
"Nitrite" (toxic as well) then converted by a second type of bacteria into
"Nitrate"(basicaly harmless in low concentrations) that gasses off in the Aquarium.
This read is not for the advanced water chemist, this read is directed to
those fishkeepers that do not know what the nitrogen cycle is, and have had problems with keeping fish alive and well in their new tanks and with new filtration...
OK to start off there are a few things that you are going to have to have PERIOD...
1)Water test kit (Ammonia,Nitrite,Nitrate)
2)patience
3)Commitment to cycle the tank completely
4)Pure household Ammonia (clear w/no soaps or fragrance)
a)shake bottle- if there are bubbles - no good
if it looks like water - way good
5)Aquarium needing cycling with the water set to 85 degrees F.
6)Filtration, installed and working properly.
First thing, first...
Bacteria thrives in water over 80 degrees F.
Make sure to set the temp to 85 degrees F.
Once you determine how much water you have in the system, de-chlorinated the water with a de-chlorinator that does not contain anything that says "eliminates ammonia etc." I use stresscoat and I know that works.
Now, you'll add 5 DROPS of Ammonia per 10 gallons, no more no less. Pick a time of day that you'll be able to take readings, everyday, for a couple of weeks.
Do this everyday until you see a measurable amount of Nitrites.
When you have a Nitrite reading, this means you have started the nitrogen cycle and are effectively growing the Beneficial Bacteria, that converts the Ammonia into Nitrite. We are half way there.
Now you will lower the amount of Ammonia to 3 drops per 10 gallons per day. You will do this until you get a reading of
0 Ammonia and 0 Nitrites. ZERO means ZERO, no matter how long it takes to get there. You are now building the Bacteria that converts the Nitrite into Nitrate.
Ok, so now we are adding 3 drops per 10 gallons of water daily.
We are getting a reading of Zero Ammonia / Zero Nitrite and we have a Nitrate reading of 20-40 ppm. You are almost there.
You need to do a 50% waterchange with de-chlorinated water and adjust your temperature. Now is the time to get your fish. Acclimate them and get them in your properly cycled tank...enjoy them as they will be enjoying your correct water parameters...