Increase of pH in tank over tap

  1. jamesonuk

    jamesonuk Valued Member Member

    Did a 70% odd water change yesterday as the tank has now finished cycling and I am planning on stocking today.

    Did some tests though to check no ammonia, nitrites and nitrates were low and all was fine. pH however was higher than I was expecting. Seems to be on the overlap between the API normaland high range tests.

    Tap is coming out as 7.0 but the tank is coming up as somewhere between 7.4 and 7.8

    I have driftwood in the tank (which I thought was meant to lower pH if anything) a single small rock and plants. Substrate is sand.

    Anything to be concerned about?
     
  2. DoubleDutch

    DoubleDutch Fishlore Legend Member

    Driftwood only lowers Ph.
    What rock and what sand ?

    Did you do earlier waterchanges or only top up water?
     
  3. OP
    OP
    jamesonuk

    jamesonuk Valued Member Member

    Sand is Unipac Limpopo and is meant to be inert. Not sure what rock is, it is not very big and was sold as aquarium rock by LFS. Will see if I can figure out what it is.

    I have done a few water changes during cycling https://www.fishlore.com/fishforum/aquarium-nitrogen-cycle/230644-nitrates-cycle-root-tabs.html (including a couple of massive ones).

    KH has constantly been 6 and GH 12 (both from tap and tank)
     


  4. OP
    OP
    jamesonuk

    jamesonuk Valued Member Member

  5. DoubleDutch

    DoubleDutch Fishlore Legend Member

    James, to be honest I doubt it is quartz or silicium, but could be calcite to me.
    Not sure though.
     
  6. OP
    OP
    jamesonuk

    jamesonuk Valued Member Member

    I guess the test will be to put the rock in a bucket of treated tap water. I can check pH before adding rock and then again a week later?? (and if rock is raising pH then I guess tank pH will drop; will be doing a 20% water change next weekend too)

    The Dwarf Rainbowfish that are in there look like they prefer alkaline water anyway so probably not a big issue at the moment but looking at adding some tetras which is more problematic.
     
  7. DoubleDutch

    DoubleDutch Fishlore Legend Member

    A stabil one is more important than a low one.
    But it still is quite "strange".
     
  8. A

    AlyeskaGirl Fishlore VIP Member

    To test the true pH reading of the tap is that you have to let it gas off for 24-48 hours with an airstone. Put some in a bucket with an airstone and test 24 hours.
     
  9. OP
    OP
    jamesonuk

    jamesonuk Valued Member Member

    Have been reading this and I think some people in this area have had similar where pH is ~7 but goes up once whatever the water company add to the water evaporates. Don't have an air pump at the moment so I have put some tap water in a bucket and will leave it 24 hours and measure pH again
     
  10. CindiL

    CindiL Fishlore Legend Member

    Hi, It is pretty common to have CO2 in the water (especially in a well) which depresses ph. As it off gasses your ph will rise to its "normal" state. The best way to do this is with an air stone but if your tank has now been running since yesterday it should be at its true ph so I would test it.

    The key here, in general, is to make sure to keep within a .5 net change during water changes once your fish are in, which should not be hard to do with that difference.