Welcome to Koi Forum. Is this your first visit? Register
Results 1 to 11 of 11
  1. #1
    Senior Member Rank = Yonsai Mode's Avatar
    Join Date
    Apr 2018
    Location
    Little Waltham, Essex
    Posts
    150
    Thanks / Likes
    264

    Water Readings - Time Of Day Effect

    Hi All

    Just thought I would post up images of the Seneye readings I get - time of day affects all three (new pond so filters maturing):-

    Screenshot 2019-06-18 at 10.53.55.pngScreenshot 2019-06-18 at 10.53.49.pngScreenshot 2019-06-18 at 10.53.43.png

    I wonder if the main effect on PH and NO3 is Algae - my phosphates are high (Rowaphos just added in filter system) and once this is lower will this change? Or do the fish produce more waste during the day etc!

    Am sure some of you will tell me exactly what causes these fluctuations!

    Cheers

    Mode


    10,118Gal 46,000l
    Nexus320
    Cloverleaf GenesisII(5 bay)
    2x13,000lph pumps, 2xEvoAqua75wUV
    11 Koi

  2. #2
    The variations in pH are due to photosynthesis but one way to look at photosynthesis is to consider that it doesn't cause pH variations, it restores your pH to its normal value. That may seem odd but this might make pH variations easier to understand:

    Measure your pH at the end a sunny day when photosynthesis has removed as much of the dissolved CO2 as possible and call that your natural pH. Measure it again as early as possible in the morning and the difference between the two is caused by dissolved CO2 due to fish respiration.


    If there were no fish in the pond there would be no downward night time change, due to dissolved CO2, for photosynthesis to restore or, if you suddenly added a load of fish without altering the aeration, the reduction due to the increase in dissolved CO2 would be greater. So, photosynthesis then can be seen as helping to restore the natural pH by removing the variable parameter (dissolved CO2) that lowers it rather than photosynthesis causing an upward variation.

  3. Thanks keithatrax Thanked / Liked this Post
  4. #3
    Senior Member Rank = Yonsai Mode's Avatar
    Join Date
    Apr 2018
    Location
    Little Waltham, Essex
    Posts
    150
    Thanks / Likes
    264
    Thanks Manky - I get the photosynthesis point but if i had zero algae photosynthesis would stop?

    If the phosphate drops, algae drops perhaps the PH will be more constant?
    10,118Gal 46,000l
    Nexus320
    Cloverleaf GenesisII(5 bay)
    2x13,000lph pumps, 2xEvoAqua75wUV
    11 Koi

  5. #4
    Yes, if you had no algae or cyanobacteria, then the effect of photosynthesis trying to restore the pH level that had fallen during the night due to fish respiration would stop. The pH would then fall to the value dictated by the ability of the aeration to remove excess CO2.

    If you increased the aeration so that it could gas off excess CO2 then there wouldn't be any pH variation whether on not you had any algae in the pond.

  6. #5
    Quote Originally Posted by Manky Sanke View Post
    Yes, if you had no algae or cyanobacteria, then the effect of photosynthesis trying to restore the pH level that had fallen during the night due to fish respiration would stop. The pH would then fall to the value dictated by the ability of the aeration to remove excess CO2.

    If you increased the aeration so that it could gas off excess CO2 then there wouldn't be any pH variation whether on not you had any algae in the pond.
    This is the reason, why on ponds with large shower filters you see typically smaller variations in pH during the day - as showers are greatly aerating the water and efficiently degassing CO2 out of the water - so either you add stronger aeration to your pond or add good shower filter instead....
    You get what you pay for - or better - what you make yourself.

  7. Thanks RS2OOO Thanked / Liked this Post
  8. #6
    Moderator Rank = Supreme Champion Feline's Avatar
    Join Date
    Aug 2013
    Location
    Somerset
    Posts
    6,653
    Thanks / Likes
    5635
    I often put my bottom drain air domes on a timer in the summer months to be on at night but not much in the day, as this helps even out pH swings.

    Unfortunately your pH runs on the higher end, which is causing more of your ammonia to be in the toxic form. I had issues like that in my pond before I started running RO. Although in theory running a low KH ought to make my pH less stable, it is actually more stable. Hard to explain really!

  9. #7
    Senior Member Rank = Yonsai Mode's Avatar
    Join Date
    Apr 2018
    Location
    Little Waltham, Essex
    Posts
    150
    Thanks / Likes
    264
    Yeah I do think RO is the way forward - just need to fin the funds to get a large RO unit!
    10,118Gal 46,000l
    Nexus320
    Cloverleaf GenesisII(5 bay)
    2x13,000lph pumps, 2xEvoAqua75wUV
    11 Koi

  10. #8
    Member Rank = Nisai AJB's Avatar
    Join Date
    Oct 2018
    Location
    Kent
    Posts
    59
    Thanks / Likes
    44
    Very interesting thread. I run a lot of air into my pond, which does disturb the water quite a bit. Based on threads here I stopped adding air and within a week was recording large pH variations but didn't know why. As I had changed nothing else I ramped up the air again and pH swings went away.

  11. #9
    That's exactly what I referred to in my post above. It's the build up of CO2 from fish respiration that lowers the pH during the night when there is no photosynthesis to remove it. During the day, photosynthesis removes CO2 and restores the pH to its correct level that the pond would have had if there were no fish in it.

    Vigorous aeration gasses off excess CO2 and prevents the pH from falling. When you had no aeration, the pH could fall during the night but the daytime photosynthesis restored it again so you had variations.

    When you turned the aeration back on, the excess CO2 was blown off so there was little or none for the daytime photosynthesis to remove and the variations ceased.

    As I said above, photosynthesis doesn't artificially raise the pH. Excess CO2 lowers the natural pH of the pond and photosynthesis restores it again. So fish respiration is what actually causes the variations and photosynthesis only restores it. Variations can therefore be avoided by increasing the level of aeration.



  12. Thanks Mode, AJB Thanked / Liked this Post
  13. #10
    Senior Member Rank = Yonsai Mode's Avatar
    Join Date
    Apr 2018
    Location
    Little Waltham, Essex
    Posts
    150
    Thanks / Likes
    264
    So here is an interesting one!

    Finally got round to adding Rowaphos to the filter system to drop the phosphate level and hopefully reduce algae and get clearer water!

    Anyway, added last night and this morning the HN3 has dropped massively! How has that happened.................

    Cheers!
    10,118Gal 46,000l
    Nexus320
    Cloverleaf GenesisII(5 bay)
    2x13,000lph pumps, 2xEvoAqua75wUV
    11 Koi

  14. #11
    Senior Member Rank = Yonsai Mode's Avatar
    Join Date
    Apr 2018
    Location
    Little Waltham, Essex
    Posts
    150
    Thanks / Likes
    264
    Amazing - NH3 still dropping!

    Full water test tonight and see what else Rowaphos has changed!
    10,118Gal 46,000l
    Nexus320
    Cloverleaf GenesisII(5 bay)
    2x13,000lph pumps, 2xEvoAqua75wUV
    11 Koi

 

 

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT +1. The time now is 06:18 AM. Online Koi Mag Forum
Powered by vBulletin® Version 4.2.3
Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.

vBulletin Improved By vBFoster® (Lite Version), © UltimateScheme, Ltd.