ammonia spike when adding new fish Question

Discussion in 'Aquarium Nitrogen Cycle' started by jerilovesfrogs, Apr 16, 2010.

  1. jerilovesfrogsFishlore VIPMember

    hi...i have a 20g that is cycled with tss. i started it on 3/15 with 2 galaxy rasboras, and 2 harlequin razzys. so two weeks after that i got two more of each, a total of 8 on 3/29. on 4/5 i added two nerite snails......and had 4 guppies in for two days before i took them out to put in Q. i wanted to make sure they were fine, plus didn't want to overload the tank.

    well, there was a small ammonia spike.... .25 on 4/6. and by 4/14 it's .50-1.0. How long does a spike last after putting more fish in? on 4/8 i tested for nitrate and it was 5-10.

    i did a gravel vac on 4/4, but forgot to do one the next week, so i just did one on 4/14. it was dirty.....could that be the cause for the spike? as well as the new fish? i'll be testing for nitrite and nitrate again tomorrow. amm today was still around 1.0 grrrrrr.
  2. midthoughtWell Known MemberMember

    I'd say increase the frequency of your water changes if you're experiencing a mini cycle -- everyday or every other day if you can manage it. Treat with Prime if you can. I'm not sure how long an ammonia spike should last...several factors would affect it, including how many new fish you put in, your tank temp, etc. I wouldn't think that *not* doing a gravel vac caused a mini cycle. As far as I know, vacuuming *too much* can cause a mini cycle but that doesn't sound like the case here. Basically your source of ammonia increased and your bacteria haven't caught up (which sounds like the case) or your pool of beneficial bacteria took a hit somehow (like got killed off by untreated chlorinated water or you threw out something with a lot of bacteria on it [filter cartridge, substrate]). Either way...your course of action is the same. Do extra water changes and wait until you're reading 0 ammonia, 0 nitrite, and some nitrate.
  3. jerilovesfrogsFishlore VIPMember

    well my filter is an aquaclear 50. the 3 stage thing with carbon, sponge and biomax pellets. well soon after i finished cycling, to make room for more media to take for my qtank, i took out the carbon. that thing was maybe that, plus the new fish/snails put me in this mini cycle. bummer. maybe i should have waited a bit until the other two had more on them. idk.

    i do use prime.....
  4. midthoughtWell Known MemberMember

    Well then great, treating new water with Prime or even dosing with Prime when you don't have time for a water change will help neutralize the ammonia and nitrite until the bacteria build back up. And you've probably identified the problem right there -- removal of some media + new fish. I'm guessing it was a carbon pad? If that helped to cause a minicycle it was probably the removal of the physical thing that some of your bacteria lived on, rather than any chemical filtration that the carbon was doing. That's my guess, anyhow.

    Good luck with it. I'm sure they'll cope well if you dose Prime for the duration of this minicycle.
  5. jerilovesfrogsFishlore VIPMember

    good thing you can dose with it when you dn't have time for a wtr change! cos i've been doing that. the razzys don't show signs of i'm glad. the carbon wasn't a pad per se, it was a huge bunch of carbon in a little mesh bag type thing.

    so i guess if it was the removal (plus the fish), then what would stop the tank from going into a cycle once it was time to change another component of the filter? like when it's time for the big sponge to will i not to thrown into a mini then?
  6. midthoughtWell Known MemberMember

    I'd just double up on it, i.e. put in the new media and keep the old one in for a couple weeks. That way, a good base grows in the new media before you totally get rid of the old media. If it's a cartridge and two don't fit, what I've done before (maybe out of paranoia) is just leave the old cartridge out in the's kind of unsightly for a little bit but I haven't experienced a minicycle yet. ;D