Question about starting a new tank with old filter with Nitrates.?

go ahead, use that tank , if it's new water , clean gravel , clean filter then u may use it . i have a tank at home with 16 fish , the tank is real big , the problem that i had was that the water is getting green every week , i realized that i had to clean the filter and while i was looking at the filter it was covered with dirt and bacterias, u gotta watch out from that.

Typically, it takes at least 30 days for a new tank to cycle...you can certainly use an old filter to start a new tank, but don't be too hasty to put any fish in it for 30 days...it will look good for about 3 or 4 days...then it will look awful and cloudy for about 2 weeks...magically, after about 30 days, the water will clear and will be ready for fish..introduce a few at a time...no need to overload a new bio-system.

There is more beneficial bacteria in the gravel and rocks than in the water, but every little bit will help to "seed" the new tank.

Be patient and resist adding any fish for at least 30 days...unless you want to cycle the tank with a few inexpensive goldfish or guppies...not a bad way to go, either. You can put them in on day one and feed them lightly....but give the tank 30 days to stabilize.

would you not want the fish in there with and old filter ?the bacteria is in the filter already and without the fish in the tank producing waste ti feed the bacteria it would make sense the bacteria would die out.old filter and old water and gravel the tank should be ready for fish right away