Mebbid
Aquarium Advice Addict
The excel isnt the problem. I dosed 30ml daily in my 55g.It is a 55 i cycled it for around three months with a goldfish then I added plants and removed the goldfish so it didn't eat anything. I then did a large water change and then added the fish. It seems I may have overdosed excel accidentally It only is killing swordtails and had no effect on my shark or black phantom tetra. The shark jumped out of a filter cut out in the glass canopy and missed a bucket of water by about two inches.
If you're showing 0ppm Nitrate then you have ammonia. Doing 10g water changes isn't anywhere near enough to remove the ammonia in the tank. I would do daily 50% changes until you can get an ammonia tester.