Ideal time to dose Alk and Ca?

Discussion in 'Reef Chemistry' started by kinetic, Sep 19, 2018.

  1. kinetic

    kinetic Supporting Member

    My tank only consumes a little bit of both right now. I've been dosing 24 hours a day using a Neptune DOS. I don't run a reverse light schedule fuge, and I don't test for ph.

    I'm only dosing 2.5 ml of Aquaforest 1+ and 1 ml of Aquaforest 2+, so I don't think my ph changes from the Alk at all. My SPS are definitely starting to grow faster, so I've been increasing my dosing every week or so lately. At some point, I wonder, if I should only dose Alk when the lights are off to help with ph. Not sure if ph is an issue at all, but if it would help even a bit, maybe I should do that.

    The other thing is, from Randy Holmes, it looks like most tanks have the most consumption of Alk during daytime hours (and shortly after). So to maintain a constant amount of Alk, it might be better to dose during the daylight hours as long as ph isn't swinging too much.

    Since I don't test for ph, and my alk amount is small, I'm considering just dosing Alk during the day, Ca at night (just to avoid clashing) or continue all day.

    Any thoughts? I know it's probably not a big deal and I should just leave it, but wanted to discuss just in case there's something slightly better I could be doing.
    JVU likes this.
  2. JVU


    I tried to find a definitive answer to this about a year ago, and didn’t find one. There are various theoretical arguments for night dosing, day dosing, and around-the-clock dosing. Once a day dosing is also popular for low-consumption tanks (and probably is the most common way). So I just do around-the-clock dosing with my DOS.

    The 2 pieces of info I haven’t seen yet that are doable would be-

    1. Alk level graph frequently measured throughout the 24h cycle with continuous supplementation, using one of the new automated alk measuring devices. To show consumption timing better.

    2. A BRS investigates type of experiment to see which option results in better growth/health.
    Coral reefer likes this.
  3. Gablami

    Gablami Guest

    At the moment, you’re not really dosing enough for it to matter. But for theoretically larger volumes, answer the question of whether you would prefer your alk to swing or your pH to swing. I would prefer alk to be stable and let my pH do what it wants.

    Sent from my iPhone using Tapatalk
    biophilia and Coral reefer like this.
  4. I do small doses of both throughout the day and night. Basically every other hour for each and alternatively, I'll dose 1/12th of my total. To clarify -- I dose 140 mg of each so I dose 1/12th of Alk every other hour and 1/12th of Calc on the alternating hours.
    biophilia likes this.
  5. Flagg37

    Flagg37 Supporting Member

    It’s a good question to ask since the alk monitoring devices are becoming more populous. Since in the ocean a coral has a nearly endless supply of alk you can make the argument that we should mimic that and try to keep it as stable as possible. I remember seeing one of the alk monitors demonstrated and he was showing that the alk in his reef tank would swing as much as 2.0dKh in a 24 hour period. I was a bit surprised at that and still a bit skeptical but without dosing (or dosing consistently throughout the day) there will be a natural swing based off of the uptake of the alk since the consumption of the alk is not consistent. So with the alk monitors we should be able to more closely dose based off of uptake throughout the day instead of just a daily amount.

    It will be interesting to see the alk graph overlaid on the pH graph to see what the chemistry does. Like @Gablami said, I would still prioritize the alk over pH though.
  6. I disconnected my PH probes. :)
  7. kinetic

    kinetic Supporting Member

    Thanks for the thoughts all!

    I think it would be great to see more of the Alk monitoring device outputs from people.
  8. Flagg37

    Flagg37 Supporting Member

    @scuzy didn’t you get an all monitor? Does it have any kind of graph that you’re able to show us?
    kinetic likes this.
  9. tankguy

    tankguy Supporting Member

    I’m gonna be the lone renegade and say I only dose when needed. I test for alk 1-2 times a week. If I need to add some alk I’ll dose the tank and bring it up slowly. Been doing it that way for years
    kinetic and Edgar Sandoval like this.
  10. Rostato

    Rostato Supporting Member

    If you have the dose, just let it do it’s thing. It’ll keep it as stable as can be.
  11. Edgar Sandoval

    Edgar Sandoval Supporting Member

    Bob I got a bubble magus dosing pump u can have. I’ll set it up for u if you want it.

    Sent from my iPhone using Tapatalk
  12. tankguy

    tankguy Supporting Member

    Let me look at it and then decide. We'll hook up soon

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