+ Reply to Thread
Results 1 to 4 of 4

Thread: pH spike, low kH, assume it's down to the scrubber?

  1. #1
    Banned
    Join Date
    Mar 2009
    Location
    UK
    Posts
    461

    pH spike, low kH, assume it's down to the scrubber?

    Hi, tonight I found that my pH had spiked to 8.8 (from 8.1-ish yesterday)

    Nothing had been changed in the tank.

    I measured the kH and it was very low, between 40 and 50 ppm (about 2.8 dKH), I had previously tested it as low (80ppm) a few days ago, but I had suspected a faulty test as the system is only a little over 2 weeks old and the water was made with a well regarded marine salt (Tropic Marin Pro-Reef)

    The scrubber seems to be really steaming on at the moment, I cleaned it on Sunday morning and it's almost recovered the screen now (hair algae, not as long as it was yet) in just 60 hours.

    Ammonia & nitrite are zero and nitrate is below 5.

    I know that heavily planted tanks can cause kH to fall and pH to spike so I assume that this is probably down to the growing algae taking carbonate from the water?

    I've got the pH down to 8.2 by adding quite a lot of Sodium bicarbonate (all I have at the moment) but haven't retested the kH yet.


    Questions are -

    1. Does the above give a reasonable explanation?

    2. What should I be dosing in terms of kH (and anything else) to counteract the effects of the scrubber and how often?

  2. #2
    Banned
    Join Date
    Mar 2009
    Location
    UK
    Posts
    461

    Re: pH spike, low kH, assume it's down to the scrubber?

    Retested the kH and it's about 130 ppm now (7.28 dKH)

  3. #3
    Administrator
    Join Date
    Oct 2008
    Location
    Salt Lake City, Utah, USA
    Posts
    10,566

    Re: pH spike, low kH, assume it's down to the scrubber?

    Alk hardly ever is reported as falling, much less a problem. I think only way your pH could be that high is with dosing kalk. Algae does use some alk, but probably less that the tank does.

  4. #4
    Banned
    Join Date
    Mar 2009
    Location
    UK
    Posts
    461

    Re: pH spike, low kH, assume it's down to the scrubber?

    Quote Originally Posted by SantaMonica
    Alk hardly ever is reported as falling, much less a problem. I think only way your pH could be that high is with dosing kalk. Algae does use some alk, but probably less that the tank does.

    I haven't dosed any kalk, or anything else, except the sodium bicarbonate.

    I read that plants/algae can use carbonate instead of CO2, this scrubber is fed from the return pump on the sump and so I guess that there won't be much CO2 in that water? Could it be drawing the alk instead of CO2?

+ Reply to Thread

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts