Question; can you take a cup or two of existing tank water in a cup/bowl and swish/rinse the filter in there?
Rastoma, I did buy and use Tetra Safestart..............
All because I never shook nitrate test bottle #2 as directed, yes stupid of me
I can appreciate wanting the best environment for your fish. But 40ppm is not bad for the fish. It's not stressful. Just because 10-20ppm is the 'target' range that people around here shoot for, doesn't mean 40ppm is awful. The water will continue to stabilize once you add fish. Then you do regular water changes and try to get the nitrate down to the target level. Fish lived wonderful, happy lives for decades with nitrate 80-100ppm. They bred, thrived, were healthy. New science, new technology, etc. now has gotten people to want 0 nitrate..