My tanks have cycled!!!!

Discussion in 'Aquarium Nitrogen Cycle' started by not4you, Mar 6, 2006.

  1. not4youValued MemberMember

    Well my 55 and 10 as of today are officially cycled! They both can consume 3 ppm ammonia in 24hrs and both ammonia and nitrite are back to 0 ppm. I've dropped the temp down to around 77 in both tanks and it will soon be time to head to the LFS for some new fish. But before that I have a concern about the pH in the 55, here goes...

    Once I started cycling the tanks here is how the pH readings have gone:
    Date pH Notes
    2/19 7.6 Filled with tap water (dechlorinated) and added ammonia to 6 ppm
    2/22 7.8 Ammonia was still 6ppm, no more had been added
    2/23 7.7 Ammonia was still 6ppm, no more had been added
    2/26 6.8 Ammonia starting to fall, down to 3 ppm
    Later that night ammonia dropped to 0, brought back up to 3 ppm
    2/27 6.9
    2/28 6.7
    3/1 6.0
    3/2 6.0
    3/2 7.3 After a MWC (~99%) to get my nitrite reading down
    3/3 7.2
    3/4 7.6 This is when the nitrIte --> nitrAte bacteria started kicking in
    3/5 6.2
    3/6 6.0

    The pH in the 10 gallon pretty much mirrored what the 55 did up until the MWC (on both tanks) of about 99%. Since 3/2 the pH in the 10 has stayed pretty steady at 7.2 as of yesterday. Today is read 7.0 but I did add some driftwood to the tanks last night. I'm pretty confident that the 10 is ready to be stocked after another MWC but the 55 I don't know ???

    Anyway to make a long story short, should I be concerned about the pH fluctuation in 55? Or once I drain and refill it in preparation for fish will the pH stabilize?

  2. ButterflyModeratorModerator Member

    After your tank cycles you really don't want to drain and re-fill it. the water is ready for fish when it's cycled.

  3. not4youValued MemberMember

    The tank is ready for fish but I really don't think the water is. First off there's a ton of nitrates in the water that need to come out and what about the pH being 6.0 (maybe lower I don't know because the test only goes to 6.0) while my tap water pH is around 7.6?

  4. EmpPlecoWell Known MemberMember

    Well, the tank really isn't cycled yet if there are still a ton of nitrates. It's close though, lol just be patient. About the pH -- I am not sure about that...?
  5. not4youValued MemberMember

    Am I just missing something here ???

    I thought the only way to get nitrates down is by changing water?

    I also thought that a tank is considered to be cycled when after spiking ammonia to 3 ppm and then in 24 hrs having 0 ppm ammonia and nitrite?
  6. AnnaEAValued MemberMember

    A thought on pH --- just a newbie here, but this is what occured to me... ammonia is a base -- could your fluctuating pH readings be connected to your adding ammonia? I noticed that the pH started to drop when the ammonia eaters started working and spiked again when you did the water change - which would have reduced your bio-filter a little bit. I assume you've been feeding it ammonia through out....

    Have you tested your kH, to make sure you've got a good buffering capacity?

  7. not4youValued MemberMember

    Anna, yes I have been feeding the tank ammonia through out the whole process and I have not tested for kH.

    However, the pH in my established 20 gallon tank is a steady 7.6 just like my tap water. Plus the pH in the 10 gallon tank has not bottomed out like the 55, although it is lower than my tap water. This leads me to believe the pH dropping is somehow related to the tank consuming the ammonia.

    Here's my current plan:
    Today - nothing, I already dosed the tanks with ammonia this morning.
    Tomorrow - no ammonia in the morning, after work refill the tank with fresh water to a) get the nitrates down and b) to bring the pH back up to around 7.6. Then add a little ammonia.
    Thursday - check water levels after work and if nothing is out of whack off the LFS
  8. 0morrokhFishlore VIPMember

    Actually the tank is cycled. You are probably thinking of nitrItes, from which you get NitrAtes which can only be removed through water changes. If your water is very soft, and therefore lacks "buffering capacity", or the ability to maintain a stable pH, that could be the cause of your problem. In aquariums, the pH should probably be a little higher than the tap water at first, due to extra oxygen in the water. After that, it will remain stable or start dropping over time if you have no pieces of rock or gravel that will harden your water. Such big fluctuations in pH should not be happening, but whether it's because of ammonia, softness, or possibly a faulty test kit or incorrect use?, I don't know. Don't get fish until the pH is under control.
  9. not4youValued MemberMember

    I guess I should test my water and find out the hardness. Should I test for both General Hardness & Carbonate Hardness?
  10. ButterflyModeratorModerator Member

    Yes you can lower Nitrates by doing water changes, but you still don't want to do 100% water changes. Another good way to get your Nitrates down is to add a ton of live plants, they will eat those Nitrates right up :)
    Once you add your fish they will add ammonia to your water, but depending how many they may not add as much as you are for your cycle.
    Run a glass of water and let it sit for 24 hrs then test your ph. this should tell you what your ph is after it gasses out.
    also test it before you put the ammonia in it could definately be affecting your ph, and should level out when you quit adding it.
  11. EmpPlecoWell Known MemberMember

    Im sorry -- I usually hear that a cycled tank has 0 ammonia, 0 nitrites, and less than 20 (as close to 0 as possible) nitrates. If someone still has an abundance of nitrates, I would NOT think of the tank/water as cycled, especially if he/she is considering doing a 100% water change as a precautionary measure to the amount of nitrates he/she has.
  12. not4youValued MemberMember


    Thanks for the advice. What's the disadvantage of changing most (just about all) of the water in the tank since there are no fish in there? I do have a few plants in the tank and I'd love to put more in there but I think my wife might kill me if I keep spending money ;).

    I realize that when I add fish (I'm not going to fully stock the tank even though I've read that a fishless cycled tank can support a full bioload right away) they won't produce the same amount of ammonia that I've been adding during the cycle.

    I've already tested water that has sat for 24 hrs and the pH remains pretty much the same. I have not added any ammonia to the tank since early yesterday morning so this is the first time the tank has set with 0 ammonia for 24 hrs. I'll check the pH when I get home this afternoon to see if there's any difference.

    How long will the bacteria survive in a tank without being fed ammonia?
  13. not4youValued MemberMember

    If nitrates are removed by doing water changes how would they ever come down without changing the water?

    They could come down via partial water changes but I'd need to keep feeding the tank ammonia to keep the bacteria alive and which would inturn produce more nitrates.

    I just don't see how you can add fish to a fishless cycled tank without doing a massive water change a day or so before you plan to add fish.
  14. vinWell Known MemberMember

    If you do a wholesale water change, your water is no longer conditioned. Partial water changes is all that are needed provided your water reading warrant a change at all. The beneficial bacteria are not only in your substrate and fiter, but they are also suspended in your water. Personally, I'd be concerned about the constant fluctuation of the pH levels......Adding ammonia will cause this to fluctuate. Too low of a pH will not produce enough bacteria to consume ammonia. Too high a pH produces more ammonia and slows down the bacteria growth as they cannot keep up with the ammonia production......It's important to remember that you're not only cycling the gravel and decorations, but the water itself.......

    You do mention your pH levels and Nitrate levels often, but no mention of ammonia or nitrites....I assume that these are at -0-?

    I would stop adding ammonia altogether. Just because you have not added any for a day it does not mean that it has cycled out. This will never condition your water and only prolong your ability to add fish safely. Since ammonia and nitrites are toxic to fish they should read -0- before you add fish. Nitrates are toxic to fish as well, but nowhere near as toxic as the other two chemicals....Which is why levels as high as 20 ppm are considered safe, but in the danger zone.

    When your tank is ready for fish your readings should look something like this:

    pH - 6.8-7.2 (range)
    Ammonia - 0
    Nitrites - 0
    Nitrates - <5

    If you want to feed your tank until you get fish, use fish food. This uneaten food will decay and produce ammonia naturally, but at a much slower rate than just pouring in a few capfuls. As soon as your readings hit the optimal range, add your fish and begin your routine maintenance program.
  15. not4youValued MemberMember

    My current readings are:
    Ammonia - 0
    Nitrite - 0
    Nitrate - off the chart

    Since Saturday my tank has been able to remove 3 ppm ammonia in 24 hours (0 ammonia and 0 nitrite) so the bacteria are there and doing their thing.

    I'm going to check the pH again when I get home and then I might go out to my LFS and pick some brains there in-person.
  16. vinWell Known MemberMember

    If your nitrates are off the charts with 0 ammonia then take a reading today and if they haven't gone down, do a partial water change of about 30%. With no ammonia to feed the nitrates they will eventually come back down to earth.
  17. not4youValued MemberMember

    Well I tested the water again this afternoon when I got off work and the pH is still 6.0. So I decided to take a trip to my LFS to ask some questions in-person as they seem to be pretty knowledgable. No offense to anyone here on the boards but sometimes a little face to face chat with someone can answer more ?pm (?pm = questions per minute :) )

    I talked to a couple of guys about my situation and they seem to think that I should just stop adding the ammonia and monitor the pH over the next few days. They suspect that without the addition of ammonia for a few days the pH will eventually come back up. I asked the one dude who seemed to really know his stuff how long the bacteria would live without food (ammonia) and he said about two weeks. Does that sound right to you guys?

    vin, regarding my nitrates. I'm more worried about my pH reading so I'm not going to change any water right now as I don't want to falsely change it. If, no WHEN (thinking positively here) my pH reading comes up I'll then change out some water to bring down the nitrates.
  18. EmpPlecoWell Known MemberMember

    Is there a way you can tell us exactly what your nitrates are?
  19. vinWell Known MemberMember

    That's fine. As I said, without the constant addition of ammonia, the nitrates should come back down to earth. But you should be just as concerned with your nitrates as you are with the pH........

    Here's a synopsis of how my cycle went - keep in mind the seemingly knowledgeable guy a the LFS advised me to add fish to kick start my cycle.

    When my ammonia was off the charts - 8.0+ the pH bottomed out to 6.4. Nitrites started and then disappeared after a couple of days.....I did a one time massive water change of over 50%. Afterward, the ammonia level was back down in the 4.0 range. The pH climbed to 6.6 and stayed there for a couple of days.

    Next, the nitrites really started to kick in and the ammonia had peaked at 4.0 and stayed there while the pH leveled off at 6.6 for several more days......

    As the nitrites kicked in, the ammonia began to discipate. The pH began to climb back into the 6.8 range and the nitrates kicked in. After a week of daily water changes of 30% (remember, I have fish in my tank), the ammonia disappeared within 3 days and the nitrites never got above .5 ppm. The nitrates never got above 10. I haven't done any water changes since last week when my water readings showed to be in the optimal range, but just for my own curiosity I tested the water yesterday.

    pH - 6.8
    Ammonia - 0
    Nitrites - 0
    Nitrates - <5

    This is why I say that without the ammonia, the nitrate levels will drop and stabilize and the pH should rise and stablize as well. If you're afraid of losig the nitrates, put a pinch or two of fish food in the water. That too will help the pH....

    I'm sorry, maybe you already posted this, but what is your pH out of the tap after gassing out? I know that mine is 6.8 and once the water in the tank went through the cycle it returned to that base level. That would provide you and us with a better idea of your base pH.
  20. not4youValued MemberMember

    I am concerned about the nitrates but the only way for them to come down is through water changes. I know plants can help with nitrates and I do have a few but I don't think they'll be able to remove them all them.

    I don't want to do any water changes at this time because the pH. My tap water is 7.6 and if I were to do a water change this would change my pH reading. I want to see if the pH will come up without adding anymore ammonia to the tank.

    If the pH comes back up to a decent level I will then change the water to reduce the nitrates.

    Why would I fear losing nitrates?

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