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Am I fully cycled?

Posted: Fri Jul 04, 2025 3:40 pm
by LilySang
I've been cycling my 20 gallon tank for about 3 weeks now. Ammonia drops to 0 within 24 hours after dosing to 2 ppm, nitrites are at 0, and nitrates are around 10 ppm. Is this enough to say I'm fully cycled? I'm using a sponge filter and have some Java Fern in there.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 4:34 pm
by sweetflake
If your ammonia and nitrites are consistently at 0 after 24 hours, and you're seeing nitrates, that's a good sign. How often are you testing? I'd recommend testing daily for another week to be sure. Also, what's your pH? Low pH can slow down the cycle.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 4:57 pm
by dawnbyte
I'm kinda in the same boat. My tank's been cycling for a month, and the numbers are all over the place. Sometimes ammonia's gone, sometimes it's not. It's driving me nuts.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 5:55 pm
by burglar_4
LilySang wrote: Fri Jul 04, 2025 3:40 pm I've been cycling my 20 gallon tank for about 3 weeks now. Ammonia drops to 0 within 24 hours after dosing to 2 ppm, nitrites are at 0, and nitrates are around 10 ppm. Is this enough to say I'm fully cycled? I'm using a sponge filter and have some Java Fern in there.
Sounds like you're on the right track. The key is consistency. If those numbers hold for another week, you're golden. What's your water temp? Warmer water can speed up the cycle.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 6:45 pm
by Flarex
I'd also check your KH. If it's too low, the cycle can stall. Had that happen to me once. Took forever to figure out.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 7:08 pm
by Aurorix8
Yeah, KH is a big deal. Mine was at 2 dKH, and the cycle just wouldn't complete. Added some crushed coral, and bam, it was done in a week.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 8:00 pm
by LilySang
Thanks for the advice, everyone. I'll test daily for another week and check my KH. My pH is around 7.4, and the temp's at 78°F. Fingers crossed.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 8:40 pm
by lynzor
Yo, 78°F is chill for cycling. Mine was at 82°F, and it cycled in like 2 weeks. Just sayin'.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 9:12 pm
by Chili
Temperature can definitely affect the speed of the cycle. Higher temps increase bacterial activity, but 78°F is perfectly fine. Consistency is more important than speed.

Re: Am I fully cycled?

Posted: Fri Jul 04, 2025 9:52 pm
by finwave1
I dunno, man. My tank cycled in like 10 days at 80°F. Maybe I just got lucky. Or maybe it's the Seachem Stability I dumped in there.