Poll: Acceptable daily swing in Alkalinity?

[MnFish1]

I think there is some clarification to the question that is needed. Are you talking variation between tests, which are administered at roughly the same time every day? Or are you talking about variation with the 24 hour period, which wouldn't be captured in the previous testing scenario?

In the first case I would say as little as possible (Consistantly (x) dKH every day at (y) Time).

In the second case, There will be some fluctuation, the extent depending on your livestock and how you dose. Even with a DOS splitting your daily dose over 24 hours you would still have fluctuation due to corals uptaking Alk & Cal at different rates during the day and night.

Testing at different times during the same day the min and max swings (I think is how its meant). Alk varies in the ocean itself during the day - I'm not sure there is a benefit to trying to keep it at a certain number 24/7.

 

[XNavyDiver]

What you're missing though is that during the 24 hour period that you aren't testing, your alk swings up/down. So while it may be 8 dkh at 5pm every day, every other hour in between it's not 8.

Correct. Which is why I'm going to get the Trident when it hits the market.

 

[MnFish1]

We've done a few polls regarding parameters. In each one, Alkalinity has always been considered to be the highest priority when it comes to monitoring and stability. A member, @Bryn, brought up a good question. Our goal should be minimal swing and that can be accomplished via programmed dosing, but that's not always an option for some. So I'm curious what others consider is an "acceptable" daily swing in Alk? For this discussion, we'll use dKH as our measurement. Feel free to discuss below after voting in the poll.

I like these polls - it would be nice to clarify the question a bit - because the way its worded it skews the results a bit. For example - does daily swing mean 'every day' - ie lots of people go by the old rule that 1dkh changes/day are 'ok' if youre manipulating the tank. I wouldn't think that means its good to do this every day.

Acceptable can be different things for different kinds of tanks - and their inhabitants.

 

[Myka]

What you're missing though is that during the 24 hour period that you aren't testing, your alk swings up/down. So while it may be 8 dkh at 5pm every day, every other hour in between it's not 8.

Yes absolutely. My doser doses every 30 minutes though, so there isn't much swing at all. I've tested at various points before/after each dose, and there is "no swing" (as per my definition above). I also don't note a difference testing at the beginning or the end of the photoperiod even though my doser doses evenly throughout the day and night. YMMV.

 

[awais98]

I think there are 2 variables:
1: Degree of change
How much variation

2: Rate of change
How fast is the variation.

Both the variables should be directly proportional and with a very low slope.

Eg: you ‘could’ have a 0.5 dkh change in 24 hours but if it happened once in 24 hours slowly over the 24 hours , this should be fine.
But if that same swing of 0.5 dkh happens 24 times in 24 hours...... you are screwed.

I’ve had 2 dkh swing over a month and it does not matter at all. Try that in 24 hrs. Everything Acro will be dead....