2 Months In, Totally Confused With Cycle

Discussion in 'Freshwater Beginners' started by alexp999, Apr 20, 2017.

  1. alexp999New MemberMember

    I'll start by saying I did/am doing a fish in cycle as this was "ok" according the LFS, however I since know it would have been better to do fishless.

    I have a 120L tank (31.7 US Gallon/26.4 Imperial), with 5 Zebra Danios that's been running for 2 months. I've been doing 10-15% water changes every couple of days to keep ammonia levels low and it all seemed to be going well for the first 6 weeks. I saw the ammonia rise (although never above 0.50 ppm), then it fell and I saw the Nitrite rise.

    I then waited for the Nitrite to fall, at this time I was testing only Nitrite as I'd seen the Ammonia go to zero and was just waiting for Nitrite to do the same. When it did and stayed away I thought I'd be able to get some more fish, so did a full water test and found the Ammonia was back at 0.50ppm!

    For the last two weeks, no matter what I do, the Ammonia will not drop back down.

    I'm using an API Master Kit, so thought I'd check it against a Salifert Ammonia test. The Salifert test appears to register 0, or at least less than 0.25ppm.

    So now I'm totally confused. If I test the tap water with the API kit I get 0, if I test the tank water with the API kit I get 0.50ppm and if I test with Salifert, it appears to be at or near 0.

    I can't use Nitrates as a measure either as I'm getting 40ppm straight out of the tap. I've put some Salvinias in to try and suck some of this up.

    The fish seem totally happy, they even appeared to be exhibiting spawning behaviour a few days ago.

    I've also got Diatoms spreading will widlfire, which I read is a good sign and happens after a cycled tank?!?

    I don't want to ask the LFS any more "advice", so found this site comes up a lot when searching for help. I really don't get what's happening to my tank or tests.....
  2. MikeRad89Well Known MemberMember

    What filter are you running?

    It could be that your tank IS cycled, but the turnover rate of water through the bacteria is too low and therefore not processing ammonia quickly enough.
  3. alexp999New MemberMember

    It's a fluval U4.

    I had been using it on spray bar mode, but re-positioned it a couple of days ago so I could use the top output and get more surface agitation in case it was an oxygen issue. (not that the Danios have gasped or hung around the top at all - just trying anything I can).
  4. prengmValued MemberMember

    It sounds to me like your tank is cycled too. I think just to be on the safe side I would get some type of beneficial bacteria like Fruval Cycle and add it to your tank acording to the directions. This is beneficial bacteria that should help handle the ammonia and nitrates. Some will tell you that doesn't work or that it's not worth it but I cycled my acclamation Tank in a week and a half with it.
    Last edited: Apr 20, 2017
  5. alexp999New MemberMember

    I forgot to mention for the last week, I've been adding a bacteria booster that came with my tank kit. I hadn't used it at the start as I've read they don't always do much, but I'm willing to try anything at the moment, lol. It has no date on it, so no idea how long it's been in someones warehouse.

    Which is the stuff that people have the most success with? I've seen TSS mentined alot (Tetra Safe Start?), but not seen the Fluval one mentioned before.
  6. el337Fishlore LegendMember

    Could you be overfeeding? How often have you vacuumed the substrate and rinsed the media in old tank water?
  7. alexp999New MemberMember

    I feed them once a day, they eat it all in about 30s.

    I have sand in the bottom, so it doesn't get turned over when cleaning. I just run the vac close to the surface to pickup any big bits of fish mess. I can't suck the diatoms up without pulling mouthfuls of gravel.

    I was vaccumming the bottom with each water change, but in the last couple of weeks I don't so much incase I was over cleaning. Only rinsed the filter once in that time though.
    Last edited: Apr 20, 2017
  8. el337Fishlore LegendMember

    So you have sand underneath the gravel? I might look into choosing one or the other esp as decaying matter can get in between and under the gravel that can cause a spike in levels. Rinsing the media weekly would be best. Both the substrate and media issues could be the cause of the problem.

    Also, what is the pH out of the tap and tank?
  9. alexp999New MemberMember

    It's just sand on the bottom. Surely matter can't get between it? That's why i thought you just cleaned the top of it.

    pH is about 7.6
  10. MikeRad89Well Known MemberMember

    Is flow rate as high as it goes on the u4?
  11. manzeezValued MemberMember

    get seachem prime it helps with ammonia but your api kit could be out of date
  12. el337Fishlore LegendMember

    Yes, with sand that's true. You mentioned gravel being sucked up which is why I thought you had both.

    pH is 7.6 out of both tap and tank?
  13. alexp999New MemberMember

    I meant sand, lol. Don't know why i said sucking up gravel.

    It's hard to tell on API kit on high pH range, possibly in tank it's 7.8 but it's not much different to straight from tap.

    U4 doesn't have any way of slowing it down that I can see. It's on the top output now though to try and increase surface agitation.

    API kit is dated 2021. Seachem stuff is mega expensive in the UK as it's mostly imported by 3rd parties. :(
  14. el337Fishlore LegendMember

    And you haven't rinsed the media in tap water or replaced any of it in the past 2 months?
  15. alexp999New MemberMember

  16. el337Fishlore LegendMember

    Can you do a full test for pH, ammonia, nitrite and nitrate?

    For your high tap nitrates, you could also look into nitrate reducing media to put into your filters like API Nitra Zorb and Seachem Matrix.
  17. manzeezValued MemberMember

    trust me you get what you pay for its worth every penny;)
  18. alexp999New MemberMember

    Ok done some tests this morning, before my water change.

    Tank pH is about 7.9
    Tap pH is about 7.5
    Ammonia is about 1ppm on API and 0.50ppm on Salifert
    Nitrite is 0.
    Nitrate is about 30ppm (lower than tap, hurray!)

    The diatoms are still spreading, I assume they wouldn't be doing so if the tap conditioner I'm using (API) wasn't working?
  19. Lindsay83Valued MemberMember

    From a quick Google and Amazon check, it appears that the Salifert test only tests NH4, while the API test kit tests NH3 (toxic, free ammonia) as well as NH4 (ammonium).

    If that's so, both tests are working properly, and tell you that you have .50 free ammonia and .50 ammonium, which, when put together, would give you the 1ppm API reading.


  20. alexp999New MemberMember

    Managed to get hold of some Seachem Prime & Stability, so going to switch to those and see how things go. :)