Lowering ph kill fish?

  1. dfish

    dfish New Member Member

    Hello, fellow fish(wo)men!

    So, I have a ph-controller.

    Right now my ph-level is set for 7.0-7.10.

    My KH is 3,5

    I realised that my C02 PPM level, with these measurements, is way too low for my plants and thus would like to lower my ph-levels to 6.7-6.8 to get closer to the preferred ppm.

    I have 11 zebra danios and a super red pleco ( <3 ). Will this kill them if I lower it to these levels? (sure it will be done gradually). Aquarium is 180L (48Gallons).

    Thank you!
  2. B

    Bhuij Valued Member Member

    In general, pH swings are way more harmful to fish than "less than perfect" pH levels. If you have a good way to slowly and permanently lower your pH to a given level and keep it there in a stable manner without going on a roller coaster ride, I'm guessing having a lower pH wouldn't be too terrible.

    Both your Zebra Danios and your Pleco should probably do okay in pH of 6.7-6.8. From what I'm seeing, they'll do okay anywhere in 6.5-8.0.

    The important thing is to change your pH gradually, and not do so unless you're sure you can keep it stable. Constant fluctuations between 7.1 and 6.7 would be harmful.
  3. OP

    dfish New Member Member

    Well, this is the point....I've got ph-controller, so the ph would be very stable and always between 6.7-6.8. I'm now just worried the fish will be harmed when I gradually lower my ph in a controlled way from 7.1 to 6.7. This is a one time action, so my concern is if the fish are going to suffer from this adjustment. :)

  4. B

    Bhuij Valued Member Member

    Nah. They should be fine as long as it's a gradual change. I'd shoot for adjusting down about 0.1 pH for every 1-2 days if you want to play it extra safe.
  5. OP

    dfish New Member Member

    Ok, thanks! :)
  6. clk89

    clk89 Fishlore VIP Member

    May I ask what exactly you mean by a ph controller?
  7. aniroc

    aniroc Well Known Member Member

    pH swings due to fluctuating CO2 level are not harmful to fish. It is normal for a tank with plants to have a raise in pH as plants are using CO2 during photoperiod.
    Densely planted ponds and lakes can have pH swings of up to 4 units of pH.

    A pH controller is like a solenoid: it stops injection when pH reaches a certain set value.