Hi Michael and welcome to the forum
Fish need water with 0ppm ammonia, 0ppm nitrite and less than 20ppm nitrate. Don't add any fish until the ammonia and nitrite have both come back down to 0ppm.
The fact your nitrite is going up, suggests the filter is developing and has the first group of beneficial bacteria that are converting ammonia into nitrite. Over the next few weeks more good bacteria should grow and convert the nitrite into nitrate. When the ammonia and nitrite have both gone up and come back down to 0ppm, then the filter will be cycled and you can add some fish.
If you have lots of live plants in the tank, they can use some of the ammonia and cause the levels to drop.
You can get a bucket of tap water and test that for ammonia, nitrite, nitrate and pH. Test the pH on that same bucket of water each day for a week and record the results.
What is the GH
(general hardness) and KH
(carbonate hardness) of your water supply?
This information can usually be obtained from your water supply company's website (Water Analysis Report) or by telephoning them. If they can't help you, take a glass full of tap water to the local pet shop and get them to test it for you. Write the results down (in numbers) when they do the tests. And ask them what the results are in (eg: ppm
, dGH, or something else).
Depending on what the GH
of your water is, will determine what fish you should keep.
Angelfish, discus, most tetras, most barbs, Bettas, gouramis, rasbora, Corydoras and small species of suckermouth catfish all occur in soft water (GH
below 150ppm) and a pH below 7.0.
Livebearers (guppies, platies, swordtails, mollies), rainbowfish and goldfish occur in medium hard water with a GH
around 200-250ppm and a pH above 7.0.
If you have very hard water (GH
above 300ppm) then look at African Rift Lake cichlids, or use distilled or reverse osmosis water to reduce the GH
and keep fishes from softer water.