I Think My Cycle's Stuck? Help

Discussion in 'Freshwater Beginners' started by cchassie, Apr 18, 2018.

  1. cchassieNew MemberMember

    I've been doing a fishless cycle with ammonia doing the "add and wait" method - my tank is moderately planted with substrate and 25 gallons. It's now Day 29 and while my ammonia has been going down (it takes about 24 hrs for 3-4 ppm to drop to 0.25 ppm) my nitrite stays about the same hovering between 0.50 ppm and 1 ppm and my nitrates are at about 5-10 ppm. They never really change even though the ammonia is changing. Every time that my ammonia drops to 0.25 - 0 I dose the tank again back up to 4ppm. I know the nitrite part is supposed to take twice as long, but this seems like it's taking a REALLY long time.

    Any suggestions? Here are my parameters from the last couple of days:

    Day 24 - tested only
    Ammonia 0.50 ppm
    Nitrite 1.0 ppm
    PH 7.4
    Nitrate 5.0 ppm

    Day 25 - tested, dosed 1.7 ml (2ppm) and 1.9 ml to bring ammonia back up to 4 ppm
    Ammonia 0.25
    Nitrite 1.0 ppm
    Day 25 evening - tested only
    Ammonia 0.50 ppm
    Nitrite 1.0 ppm
    PH 7.4
    Nitrate 5.0 ppm

    Day 26 - tested only
    Ammonia 0.25 ppm
    Nitrite 1.0 ppm
    PH 7.4
    Nitrate 5.0 ppm

    Day 27 - tested, dosing ml back up to 4ppm
    Ammonia 0 ppm
    Nitrite .50 ppm
    PH 7.4
    Nitrate 5.0 ppm

    Day 28 - tested only
    Ammonia 0.25 ppm
    Nitrite 0.50 ppm
    PH 7.4
    Nitrate 10 ppm

    Day 29 - tested, dosed 3.5 ml back up to 4ppm
    Ammonia 0.25 ppm
    Nitrite 0.50 ppm
    PH 7.4
    Nitrate 10 ppm
  2. mattgirlFishlore VIPMember

    That nitrite can be some stubborn little bacteria. I seems to just want to keep on hanging on. Just be patient a little while longer.

    Keep adding the ammonia so the nitrites can continue to eat. Personally at this point I wouldn't let the ammonia get down to 0. When I saw .25 I would add more ammonia.

    I have a feeling you are so very close to cycled. Ammonia drops slowly over time. Nitrites can be off the chart one day and the next day can be 0. Once they drop to 0 they usually stay there.

    Hang in there because the end is in sight.

  3. ASHLEY R COOKWell Known MemberMember

    Omg. My cycle is the exact same. I'm on day 35 and same thing. I just ordered some seachem stability to hopefully kick it into gear next week

  4. mattgirlFishlore VIPMember

    If it helps y'all at all it took me a solid 6 weeks to cycle my tank. I did a fish in cycle so was doing a LOT of water changes during those 6 weeks.

    Patience is the key to a successful cycle. I have to tip my hat to those of y'all that have the patience to sit there and stare at what looks to be an empty tank during the cycling process. Possibly the best way to go but I imagine it is a very boring thing to do.

    You do have living creatures in there. You just can't see them without a high powered microscope.

  5. A. RozhinValued MemberMember

    I know this is like a broken record, but if you can get a piece of filter media from a cycled tank, it will accelerate the process. Agree that nitrites will be super high then suddenly zero. You have the Nitrosomonas bacterias that change nitrite to nitrate because your nitrates are very slowly rising, just not enough yet to complete the whole cycle. I'd dose high ammonia, which will jack up your nitrites, and then give the nitrate-crew more to eat. Your fishless, so you can afford to try this.
  6. trainandfishguyValued MemberMember

    It seems that you are very close. Just a tab bit longer.
  7. TexasGuppyWell Known MemberMember

    4ppm/day is a really high load... 2ppm may be more realistic of a daily load. Perhaps don't dose so high and see if you hit zero.
  8. A. RozhinValued MemberMember

    She's hitting zero on ammonia, though, and then her nitrites drop. There are not enough of that bacteria, they can't grow stronger because there's not enough to eat (not able to clean their plate, so to speak).

    OP has nothing to lose by dosing higher ammonia, it's fishless. What's the worse than could happen? The ammonia could sit there until nitrites caught up? That's actually what she wants.
  9. TexasGuppyWell Known MemberMember

    Well.. yes, but once you add fish, you'll not be getting 4ppm ammonia per day... so why waste your time building up to that level.. they'll just die off once you stock your tank.
  10. A. RozhinValued MemberMember

    Yes, but you'll be cycled then. If you theory is true, everyone would do fish-in cycles with no trouble. You build up the bacteria and then let it fall back to its own level when the fish are in, with a large margin for error. This is not a personal theory, this is accepted practice for fishless cycling.

    ETA: Everything my books say about cycling say an appropriately stocked tank should be able to process 2 to 4 ppm per day. So she will not have less ammonia when she puts fish in.
  11. TexasGuppyWell Known MemberMember

    I think I'm saying 4 is a very heavily stocked tank.. 4ppm would be around 80 ppm nitrates per week.. that's pretty high.
  12. A. RozhinValued MemberMember

    First: actually, you can't make that nitrate calculation from the ammonia amount. A heavily planted tank might not get above 10 ppm on that ammonia amount. A bare one might be double.

    Also, it depends on your fish. Appropriate number of mollies vs. appropriate number of guppies? Totally different ammonia issue.

    Regardless, the number is, and you can do the research, between 2 and 4 ppm for a normally stocked tank. On what are you basing your data, since it's already a given that your nitrate calculation was pulled out of thin air...

    The OP is trying to cycle a tank, man. You're saying, "It SEEMS high." But you don't back it up except by a fantasy calculation.

    Adding more ammonia is the proper thing to do by any accepted methodology. Do you have a point? What could she POSSIBLY gain by dosing lower, when she ONLY has to gain by dosing higher?
  13. TexasGuppyWell Known MemberMember

    My calculation was based on no plants. Pure conversion rates. Plants don't make a difference when saying what is a normal bioload of a stocked tank. Either plants convert it or bb will. I just haven't read cycling up to 4 or 5 before. It just takes longer. Most people ask, when am I done? If you aren't going to fully stock a tank right after your wasting time. It won't hurt either, just sharing the logic behind picking a level that's realistic for ones usage.
    My wives 10g had 4 grown serpia tetra and two grown Mollys.. it only created about 1ppm ammonia per day..

    P.S. Dr Tim's website recommends 2ppm

    Too lazy to do my own calcs, so here is a link
    1ppm ammonia per molecular weight will convert to 3.6 nitrates.
    4ppm/day ammonia is 100.8ppm nitrates in a week.


    You tell me, is that a reasonable cycle level?
    Last edited: Apr 18, 2018
  14. cchassieNew MemberMember


    Day 35 and it finally cycled! Thank you for your advice everyone! On Sunday, I wanted to plant a bunch of plants that arrived on Wednesday of that week, I did a PWC because I couldn’t reach the bottom without splashing water everywhere and then dosed it back up to 4ppm. Left it for the weekend and then tested Monday and dosed it back up as the ammonia was zero and tested this morning and ammonia and nitrite are 0! I’ll keep an eye on it and dose the rest of the week to make sure but I think I can finally add my fishies!!

    They aren’t lying when they say it’s overnight so for everyone struggling with the end of your cycle it WILL happen!

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