Report: My Armchair Kh/ph Crash

  1. SkookulBob Member Member

    I have a filter with some Matrix in it that I use to cycle out the ammonia in my tap water prior to water changes. (Edit: my tap water has chloramine and therefore ammonia.) Between WC’s, I keep it running in a container of water (no fish), and I feed it with ammonium chloride. It works great. I have seen a people recommend cuttlefish bone as a way to keep KH up and prevent a pH crash in the event nitrification or some other process consumes your KH.

    Just to get a feel for things, I put some cuttlefish bone in the container, and fed the filter lots of ammonium chloride, repeatedly. I thought the cuttlefish bone would dissolve calcium carbonate into the water at a high enough rate to prevent a crash.

    It didn’t.

    The pieces that were in there dissolved at a pretty good rate (at least they’re noticeably smaller after two weeks or so) but the pH went from 7.5 to 6.4; the KH fell from 3.5 to less than 1.

    Maybe more cuttlefish bone would work better, or a different material, like Texas Holey Rock (love the name), or even just straight up CaCO3.

    Anyhow, FWIW.
  2. Aquaphobia Fishlore Legend Member

    Out of curiosity, why do you add ammonia to your tap water?
  3. SkookulBob Member Member

    I don’t. My municipal water utility uses chloramine, which is basically a combination of chlorine and ammonia. It has better staying power as a disinfectant, and is therefore preferable for purposes of supplying water for typical uses. But it complicates fishkeeping slightly, since it means your water effectively comes out of the tap with detectable ammonia levels. Old school thiosulfate dechlorinator will break up the chloramine and neutralize the chlorine, but it leaves the ammonia. That’s why Prime and AmQuel are so widely used–they also detoxify the ammonia but leave it available to your biofilter to oxidize to nitrate.

    I DO add ammonia (well, ammonium, but same thing for biofilter purposes) to the holding container for my Matrix filter to grow and feed the nitrifier colonies. It’s kind of a perpetual fishless cycle. But that’s just used tank water and will never go back into the tank. I water plants with it or flush it.
  4. SkookulBob Member Member

    Also, you probably know all that. I apologize; I get verbose when it’s late!
  5. Aquaphobia Fishlore Legend Member

    Ah, I see. I thought you were adding it to the water that was eventually going to go in your tank! My misunderstanding :)
  6. SkookulBob Member Member

    Now that would be a weird thing to do! I see from my original post how it could easily be read that way though. Clarified. Thanks!