fishless cycle???

Discussion in 'Aquarium Nitrogen Cycle' started by beginner, Dec 26, 2012.

  1. beginnerValued MemberMember

    ok so I've never gone fishless but, I am wondering from someone who does this, do they once the cycle is complete run out and buy twenty seven fish and just dump them in all at once??
  2. cichlidmacWell Known MemberMember

    I've always stocked slowly adding small schools first and the center piece or more aggressive fish last.

    If you want to start with more it depends how much your bacteria can handle. Are you cycling with pure ammonia? Or fish food?

  3. ryanrModeratorModerator Member

    No, definitely don't stock all fish at once.

    Even though a tank may have cycled, there is no way of accurately knowing how much bio-load your stock will produce. That is, if you cycle fishless, and get 4ppm ammonia to nitrates in 24 hours, you could theoretically stock fish that produce up to 4ppm ammonia, but it's hard to know exactly how much your fish will produce.

    I always recommend slowly stocking your tank, allowing around 2 weeks in between additions.

    EDIT: and per cichlidmac, it is always advisable to stock from least aggressive/territorial to the most.

  4. LyleBWell Known MemberMember


    How many you can stock initially depends in part on how high you dosed you ammonia during cycling. If you only dosed to 2ppm, then your initial stocking should be at about half of what your filter could handle if you consistently dosed at 4ppm, which is about as high as you should go in order to not slow the cycle down.

    That said, you still need to be patient in stocking. Even after the filter has cycled, the BB colony isn't completely stable, and things could set it back. I would start with about 5 or 6 small fish, or two or three larger fish, and keep tabs on how the filter handles it. You will probably be able to add more sooner than you would after doing a fish-in cycle.

  5. beginnerValued MemberMember

    I would never could never go fishless. I've been reading the questions and advice of the newbies wanting to go fishless. it seems to me they've all tried fish -in and failed at it. I haven't seen any advice about slow stocking, one at time. I just wondering if there gonna finally get a cycle and then think they can fully stock.

    I just dnt wanna see anyone afraid to do fish in. any time you add three you have ammonia in the tank anyway. is there a sticky for those who choose fish in?
    Last edited by a moderator: Dec 26, 2012
  6. ryanrModeratorModerator Member

    Hi, stickies exist to help those cycling with Fish:

    and also, using established media:

    There is also a ton of threads in the forum about fish-in cycling, and in the beginners forum.

    Many prefer and recommend fishless cycling as it does not expose fish to harmful ammonia/nitrites, but that said, many many new comers to the hobby (myself included) are not informed of the nitrogen cycle, and end-up battling with daily water changes and daily dosing of prime to try and save the fish.

    From a stocking perspective, a fish-in cycle also typically requires a larger number of fish to get sufficient levels of ammonia to start the cycle.

    Whether a tank is cycled using seeded media, fishless, or fish-in, the stocking rate should always be gradual (IMO), allowing a couple of weeks between stocking. No matter how it cycled, you still need to be mindful that the bacteria colony that is present, may not be able to cater for the level of fish introduced, so slow and steady is a prudent approach.
  7. beginnerValued MemberMember

    love it! great advice you gave, like to see more people say slow responsible stocking and water changes are the keys to success long term in this hobby.
  8. LyleBWell Known MemberMember

    Actually, there are two major advantages to fishless cycling.

    1) No, or should I say, GREATLY reduced stress for the fish. They are not having to tolerate too-high ammonia and nitrite levels at any time.

    2) You can get to fully stocked much quicker. Yes it takes 6 to 8 weeks with no fish, but once you start adding fish, you can add them quicker (but not TOO quick - must monitor) and still keep the ammonia/nitrite levels at 0ppm. This is because you have dosed the tank to a higher ammonia level during cycling, thus more BB grow quicker. If you do a fish in cycle, you cannot allow the ammonia level to get nearly as high, so the BB grow slower. Plus, you can raise the temp of the tank higher if you do not have fish in it. This also speeds up the bacterial growth rate. Finally, if you utilize seed material, in my experience, the time is cut about in half.
  9. beginnerValued MemberMember

    the ammonia bacteria can double in eight hours. nitrite bacteria in 13. perfect temp for both is about 75

    but you cant add fish without raising ammonia. ever. unless what you're saying is that a fishless cycle makes for a stronger breed of bb
    Last edited by a moderator: Dec 26, 2012
  10. LyleBWell Known MemberMember

    Studies I've seen state that the ideal temp is between 74 and 86 degrees F with fastest growth at the higher end. Growth slows again if you go beyond this.
  11. LyleBWell Known MemberMember

    If you have fish in the tank, you need to do daily or every other day water changes in order to keep the ammonia levels within reason, at or below 1 ppm. Each time you do a water change, you are also removing some of the food for potential bacteria growth. It becomes a balancing act between what is best for the fish, vs what is best for the growing bacteria.

    With fishless cycling, you can raise the levels to 4 or even 5 ppm. These levels would kill any fish you had in the tank. More ammonia means more bacteria will grow. Enough will grow to be able to convert 4ppm rather than just 1ppm. This higher capacity to convert ammonia, means that the tank can support more fish once the initial cycle is complete.
  12. ryanrModeratorModerator Member

    You may find the following useful/interesting:
  13. beginnerValued MemberMember

    haha that's fritz zime! I read that some where a few weeks ago somewhere. that's where I was getting those numbers
  14. holatommNew MemberMember

    I've read countless articles/threads about fishless cycling & the widely accepted methods (ammonia, shrimp, flakes, etc.) and even placing live plants (which have been in an already cycled tank) in a new setup. However I can't seem to find anything regarding the bulbs of plants used. For example, if a new aquarium is setup and one chooses to do fishless cycling, does planting bulb(s) help establish the cycle? Or rather, do the processes involved with the deterioration of the outside of the bulb & germination of a plant initiate the nitrogen cycle?
  15. ryanrModeratorModerator Member

    Plants don't establish the cycle persay.

    Plants help to consume the nitrogenous waste, reducing the concentrations of ammonia (as a preferred food, specifically ammonium NH4), which thus reduces nitrite concentrations (less ammonia to convert to nitrite), which then naturally reduces nitrate levels. In the absence of ammonia/ium, plants will consume nitrate (NO3)

    In a heavily planted aquarium, with low stocking, it is not uncommon to have very low nitrates. The plants continue consuming NH3/NH4 (ammonia/ium), and the little nitrates (NO3) that are produced in the filter, quickly get consumed by the plants too. Quite often it is necessary to dose nitrogen into a planted tank ;)

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