Fritz Turbo Start Cycling question 2 weeks in

TonyJ · Oct 2, 2026

Hi All,
I started my IM 20gallon 14 days ago. Using about 16lb dry Marco rock, 20lb Arag alive special grade sand. Filled tank w RODI mixed w Aquaforest Salt @35 ppt. Added Fritz Turbo start 900 followed by Fishless Fuel (used 4 drops per gallon of water, actual water was about 15 gallons so 60 drops) After 3 days Ammonia was 0 Nitrites around 4 stayed that way for 7 days. On day 7 or 8 I added alittle more Fishless Fuel at half dose (about 30 drops) to keep Ammonia bacteria going. Testing daily Ammonia 0 but Nitrites stuck around 3-4 range Im on day 14 now Temp in tank was around 77 I raised it to 79 now. Also confirmed test results at an old school LFS. Should I just keep waiting or add more Fishless Fuel, small water change? Thanks All
Tony

exnisstech · Oct 2, 2026

Do you have nitrate? If ammonia went to 0 and you have nitrate it's time to slowly move forward IMO. Nitrite is not harmful to marine fish. Some folks like to wait until it reaches zero but it isn't necessary.
Not a recommendation because testing to make sure ammonia is being processed is a good idea but I don't own an ammonia or nitrite test and have never had a problem proceeding slowly when I see nitrate.

Randy Holmes-Farley · Oct 2, 2026

I agree. Move on. :)

TonyJ · Oct 2, 2026

exnisstech said:
Do you have nitrate? If ammonia went to 0 and you have nitrate it's time to slowly move forward IMO. Nitrite is not harmful to marine fish. Some folks like to wait until it reaches zero but it isn't necessary.
Not a recommendation because testing to make sure ammonia is being processed is a good idea but I don't own an ammonia or nitrite test and have never had a problem proceeding slowly when I see nitrate.

Yes I do have nitrates reading around 30-40 or so . Should I do a partial WC before adding first fish?

Fish Fan · Oct 2, 2026

TonyJ said:
Yes I do have nitrates reading around 30-40 or so . Should I do a partial WC before adding first fish?

It wouldn't hurt to do a water change, but it's not necessary, in my opinion. The 'big water change after the cycle' is supposed to reduce high nitrate, but you have nitrite that causes a false high result for nitrate. For that reason, your nitrate is likely not nearly as high as your test would indicate. I would wait for the nitrite to fall to zero before deciding that your nitrate is high, and a large water change is necessary.

But to be clear, the nitrite isn't harmful, and you can safely start to slowly add some hardy livestock

Good luck!

exnisstech · Oct 2, 2026

∆ This ∆

TonyJ said:
Yes I do have nitrates reading around 30-40 or so . Should I do a partial WC before adding first fish?

TonyJ · Oct 2, 2026

Fish Fan said:
It wouldn't hurt to do a water change, but it's not necessary, in my opinion. The 'big water change after the cycle' is supposed to reduce high nitrate, but you have nitrite that causes a false high result for nitrate. For that reason, your nitrate is likely not nearly as high as your test would indicate. I would wait for the nitrite to fall to zero before deciding that your nitrate is high, and a large water change is necessary.

But to be clear, the nitrite isn't harmful, and you can safely start to slowly add some hardy livestock

Good luck!

Thank You. Will take your advice n add my first fish this weekend.