Poll: Acceptable daily swing in Alkalinity?

[dbl]

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.

 

[jsker]

Since I dose 8 times the alk should only have a very slight swing

 

[BoomCorals]

I think most acros, even the finicky ones, will be ok with just under a 1dkh swing in a 24 hour period, so long as it goes back to "normal". So for example if your alk swings from 8dk to 9dk then back to 8dkh in a 24 hour period you're fine in most cases. I'd wager your average system has a .5 dkh swing per day (unless you are trying to specifically dose to counter the swing). Ultimately though, as long as your swings are STABLE - meaning, you have roughly the same swing every day, your acros are not going to care! The stability of having the same swing every day is more important than the amount in the swing IMO.

 

[XNavyDiver]

I don't know what is acceptable or not. I can chart what happens in my tank only and observe my corals and make inferences from there. My corals are doing well. Here is what my pH and alk look like for this month.

 

[Jose Mayo]

I think minimal variations should not be a concern.

In most well-conducted aquariums, the greatest factor of alkalinity consumption is the growth of hard corals, which consume carbonates in the construction of their calcium skeleton. In unbalanced aquaria the set of causes of consumption is variable, but perhaps one of the most important is precipitation.

As for hermatypic corals, although it is clear that a discreetly high level of alkalinity favors its growth, for aspects of criticality, small changes or fluctuations in alkalinity levels are also of little value; as in the formation, growth, and maintenance of human bones, skeletons of corals are formed, destroyed and reformed all the time, at the interface of the skeleton with the polyps, being only the game of balance between the "osteoclastic" and " osteoblastic "(each driven by its specific cell group) that will define whether the coral grows or not.

In these conditions the hermatypic coral takes advantage of its skeleton not only as a structure, but also as a reserve of calcium carbonate, which makes it less dependent on the level of alkaline reserve of the medium for its growth and maintenance of the health of its structures (including repair ). Otherwise, there would be no way to explain the axial growth of the acropores, and all corals would look like something like a calcium carbonate sphere, with all the polyps producing and fixing calcium carbonate at the same time.

With this in mind, I would only try to maintain variations of alkalinity in a narrow range and make the changes of concentration, if and when necessary, in a very slow and gradual way, so as to favor the adaptation of my animals to the new level of interaction and to prevent situations such as "burnt tips" and even RTN, which usually occur when these changes are very abrupt.

Best regards.

 

[DSC reef]

I voted nothing over .5 daily. We dose morning and night and test daily. I'd love to have automated dosing but I don't trust them. Plus the tanks uptake differs day to day so regular testing helps and Hannah alk checker makes it easy

 

[XNavyDiver]

I voted nothing over .5 daily. We dose morning and night and test daily. I'd love to have automated dosing but I don't trust them. Plus the tanks uptake differs day to day so regular testing helps and Hannah alk checker makes it easy

Did you have a doser in the past and have an incident? I've dosed with the DOS from the beginning and have found it extremely reliable spreading out alk and ca+ over a 23 hour period. I dose mg+ by hand, but only because it requires such infrequent maintenance.

 

[DSC reef]

Did you have a doser in the past and have an incident? I've dosed with the DOS from the beginning and have found it extremely reliable spreading out alk and ca+ over a 23 hour period. I dose mg+ by hand, but only because it requires such infrequent maintenance.

I never have taken the plunge. It just makes me uneasy. Maybe one day I'll try it.

 

[BoomCorals]

I never have taken the plunge. It just makes me uneasy. Maybe one day I'll try it.

The key is to manually set the DOS to what you feel is needed and adjust from there. Don't let a system control your dosing based upon alk testing. I adjust my DOS up/down regularly as my load/demands change. For example when I have a bunch of orders ship, my demand drops so I'll drop from say 175ml per day to 150ml per day. The DOS takes care of the rest, spreading that out evenly over a 24 hour period.

 

[XNavyDiver]

The key is to manually set the DOS to what you feel is needed and adjust from there. Don't let a system control your dosing based upon alk testing. I adjust my DOS up/down regularly as my load/demands change. For example when I have a bunch of orders ship, my demand drops so I'll drop from say 175ml per day to 150ml per day. The DOS takes care of the rest, spreading that out evenly over a 24 hour period.

This is true, as I recently took shipment from you for quite a few corals. I adjusted my DOS from my phone to increase by 10ml. Alk stayed rock solid level.

 

[DSC reef]

The key is to manually set the DOS to what you feel is needed and adjust from there. Don't let a system control your dosing based upon alk testing. I adjust my DOS up/down regularly as my load/demands change. For example when I have a bunch of orders ship, my demand drops so I'll drop from say 175ml per day to 150ml per day. The DOS takes care of the rest, spreading that out evenly over a 24 hour period.

Thanks for the info @BoomCorals

 

[ajcanale]

A .4 or so fluctuation throughout the day (high demand system) is relatively stable IMO

 

[Justin Swinney]

Mine is usually between 8.8 and 9.2. I’ve seen no issues yet

 

[Myka]

Per day?? I think the lowest option is too much, no I picked "no swing is acceptable" because that's closer. Haha! I aim for less than 0.15 dKH daily swing. I want to read the same number every time I test. I realize test kits (and checkers) aren't accurate enough for "no swing", so I consider 0.15 dKH out of a test kit as "no swing" because that's within the kits' accuracy.

For Salifert, the resolution is 0.15 dKH and if I test 7.85 dKH today, and 8.0 dKH tomorrow at the same time, then I consider that the same, unless I test on the third day and get 8.15 dKH then I know my doser needs adjusting.

For Hanna, the resolution is 1 ppm (0.056 dKH), though the accuracy is +/- 5 ppm (0.28 dKH), so anything within 5 ppm I consider to be "no swing". As with Salifert, I'm looking for a trend - if it's going up by 2 or 3 ppm everyday, I know the doser needs adjustment.

 

[MnFish1]

It depends on the method you're using to measure alkalinity. The Hanna checker accuracy is +- .3 dkh. If you are shooting for less than .6 variation/day you wont know using this method. etc etc. Red Sea is +- .14 DKH. Looking at various websites where the alkalinity in the ocean has been measured daily for a time it seems like it varies .1-.5 dkh /day

 

[ksfulk]

Here's some graphs from my tank over the past year, month and week. I test nearly everyday for Alk, at or near the same time, so there's a bit of data. I shoot for 115-120 ppm (6.4-6.7) dKH in my system. I just moved 20+ frags from my system, so I would expect that I need to turn down my dosing a bit, but its relatively easy to do. Paying attention to your tank can really help understand what the swings are doing to your creatures and how they respond to it.

Feb 8, 2017 - Feb 8, 2018

Jan 8 - Feb 8, 2018

Feb 1 - Feb 8, 2018

 

[Rakie]

I dose 12x a day, my swing is typically around 0.1 - 0.3 daily -- right on the money for the first answer.

That said, once I switched up lighting to LED, I saw a very big change in Alk consumption, and had some BIG swing which worried me. Now that acros have settled down, things are getting a tad more normal.

When it comes to alk and stability I don't think there's a better person to bring up than Julian Sprung, who doses alkalinity every ten minutes.

Stability is king, in ALL parameters. The more stable, the better.

 

[BoomCorals]

Per day?? I think the lowest option is too much, no I picked "no swing is acceptable" because that's closer. Haha! I aim for less than 0.15 dKH daily swing. I want to read the same number every time I test. I realize test kits (and checkers) aren't accurate enough for "no swing", so I consider 0.15 dKH out of a test kit as "no swing" because that's within the kits' accuracy.

For Salifert, the resolution is 0.15 dKH and if I test 7.85 dKH today, and 8.0 dKH tomorrow at the same time, then I consider that the same, unless I test on the third day and get 8.15 dKH then I know my doser needs adjusting.

For Hanna, the resolution is 1 ppm (0.056 dKH), though the accuracy is +/- 5 ppm (0.28 dKH), so anything within 5 ppm I consider to be "no swing". As with Salifert, I'm looking for a trend - if it's going up by 2 or 3 ppm everyday, I know the doser needs adjustment.

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.

 

[chipmunkofdoom2]

I suppose what's "acceptable" varies. The first thing to consider is your livestock. If you have SPS, obviously they're going to be more sensitive to carbonate alkalinity changes. If you have soft corals, you can likely get away with much larger changes.

Second is what's "acceptable" (probably safe, but on the limit) versus what you feel comfortable doing. I've heard that swings up to 1 dKh a day are okay, while no more than 0.5 dKh per day increase is likely safer. Personally, I prefer to change my alkalinity no more than 0.3 dKh per day. I probably could go higher, sure, but I'm in no hurry. If I need to increase my alkalinity, I'll do it over a period of a week or so.

 

[Tklb]

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.