I have a 10 gallon saltwater aquarium for about 3-4 months. Everything was fine, I had 2 clownfish and a hermit crab. I was trying to start having corals because before I only had plastic rocks and plants. So by trying to do that I bought a special light called Aqua Illumination Nano Sol Modular LED
and a better filter from Eheim.
I tested the water and everything was looking good so I got 3 corals! I found a rock at the beach so I boiled it and put it outside for 3 days like my aquarium shop has said I should do. I put the corals and the rock in with my hermit crab and 2 clownfish already in it.
The next day my two clownfish were dead. I checked the water and the nitrate was at 1.0, phosphate at 0.25 and ph at 7.4. So I went to the aquarium shop and they told me that because I changed my filter and didn't leave my old filter in it that its like staring a new aquarium because there are no bacteria in the filter. So I guess thats how my fish died.
After that I did a 30 percent water change and put buffer and bacteria in. It was fine for about 6hr. I checked it again and nitrite was fine again (0ppm)the ph was at 7.4 and phosphate was still 0.25. So I added buffer to bring the ph to normal again but just a few hr later the nitrite was back to 1.0.
I don't know if I am doing the right thing....
I don't want my hermit crab and the new corals to die....