dKH ???
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Shadowramy
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Very interesting, I did a small alk study a while back and decided to look at some of the TOTM tanks over the past two years. I did throw out the one nano tank.
The average was around 8-9 however when I polled my local reef club the average was still around 10-11. I do think you have less issues with RTN running an alk of 7-8.
RC TOTM Alk Study Stats
1. 60% of the tanks have a dKh between 7-9
2. The most common dkH was between 8-9 (25%)
3. The average dKh of all TOTMs is between 8.5 and 9.8
4. There is a trend of alk getting closer to NSW. Over the first 15 months (2006-2007) alk ranged from 8.7 - 9.8. During the last 6 months alk dropped to ranges of 8.5-9.5. If I threw out the one guy running a 10 dkH the average would be a solid 8 dkH
5. 20 of the 25 tank had a dkH lower than 10. Over 50% of the tanks dkH was 9 or lower.
6. Only 3 of the 25 tanks had a variance of more than 3 points - meaning the swing range is very low and Alkalinity is very consistent and stable. No big swing of 7-11. The largest swing being 10 to 12 (3 points).
The average was around 8-9 however when I polled my local reef club the average was still around 10-11. I do think you have less issues with RTN running an alk of 7-8.
RC TOTM Alk Study Stats
1. 60% of the tanks have a dKh between 7-9
2. The most common dkH was between 8-9 (25%)
3. The average dKh of all TOTMs is between 8.5 and 9.8
4. There is a trend of alk getting closer to NSW. Over the first 15 months (2006-2007) alk ranged from 8.7 - 9.8. During the last 6 months alk dropped to ranges of 8.5-9.5. If I threw out the one guy running a 10 dkH the average would be a solid 8 dkH
5. 20 of the 25 tank had a dkH lower than 10. Over 50% of the tanks dkH was 9 or lower.
6. Only 3 of the 25 tanks had a variance of more than 3 points - meaning the swing range is very low and Alkalinity is very consistent and stable. No big swing of 7-11. The largest swing being 10 to 12 (3 points).
MCsaxmaster
New member
Why?
gavinbree
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<a href=showthread.php?s=&postid=13268782#post13268782 target=_blank>Originally posted</a> by MCsaxmaster
Alk burn???
I've heard of people blaiming higher alkalinity for problems when dosing vodka/sugar/vinegar, or when using zeovit or similar systems. Without such methods, however, I've not heard of any problems. Something strange certainly appears to be going on with high alkalinity and vodka/sugar/vinegar/etc., at least for some folks, but without such extreme methods, I see no reason to be concerned about coral health with higher alkalinity. I might be concerned about excessive abiotic CaCO3 precipitation, but I don't see any reason to be concerned about the corals.
Chris
So are you saying mother nature has it all wrong and thousands of years of coral evolution was for nothing ?
Whether high alk is bad or not is perhaps something we will never know because saltwater is very complex, but surely we should be striving to keep our parameters as close to what nature dictates as possible (which includes stability)
I do agree that it could be caused by adding vodka etc, but alk burn is normally a side effect of alk swings.
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I have always run 10-11 and never had "alk burn". I am at 11 consistently since starting my 1000 gallon system and if I notice signs of "alk burn" I will consider reducing my alkalinity to 9-10.
FWIW, I do not run zeo or any other types of additives besides a calcium reactor.
FWIW, I do not run zeo or any other types of additives besides a calcium reactor.
I think running low alk has come up in the recent year, due to, zeo and vodka dosing.
When I was running zeo it was imperative to keep alk constant and potassium at a good level or my corals would suffer colorwise and even RTN.
When I was running zeo it was imperative to keep alk constant and potassium at a good level or my corals would suffer colorwise and even RTN.
MCsaxmaster
New member
Consider some of the other things mother nature provides:
hurricanes/typhoons, extreme low tides leaving corals exposed and baking in the sun, crown of thorns starfish, cold snaps in winter, extreme low salinity after big rains, smothering turbidity, etc.
Natural does not imply ideal by any stretch of the imagination. Corals and other calcifying organisms certainly can and do grow well enough at NSW levels of alkalinity, but there's no reason to think that NSW alkalinity is the ideal situation. It may simply be "good enough", and indeed, that is exactly what all of the available data suggest.
And in terms of scleractinian evolution, we're looking at 230+ million years, not mere thousands. But, to be fair, there have been really significant secular changes in seawater chemistry during that period.
Why wouldn't we be able to know that? Ramp up the alkalinity and measure various parameters (e.g., calcification, linear extension, net primary production, etc.) and see what happens. Many such studies have been conducted, including work I've done for my master's. In every case the corals calcify significantly faster with higher than NSW alkalinity and generally have higher rates of net primary production. There has been no indication of any problems either in short-term or long-term studies that have been done in otherwise normal conditions.
See above: there's no reason to think that what nature provides is ideal but rather just good enough. If we don't have a good reason to deviat from nature, I agree that it's a good baseline--we know that will work at least well enough. However, when there ARE good reasons to deviate from nature (e.g., not putting crown of thorns starfish in our aquariums), why wouldn't we?
As for stability: if there is anything that is uncommon on shallow reefs and reef flats, where calcification is near a maximum, it is stability. Granted, corals are likely to see much more fluctuation in alkalinity in our aquariums than in most natural situations, but why would fluctuation in and of itself be harmfu? In nature they may see conditions vary from "sufficient" to "slightly marginal" in terms of chemistry. In captivity we may well be able to provide variation from "very good" to "sufficient"--that strikes me as perhaps a more ideal situation for growing corals.
You say this based on...?
Chris
MCsaxmaster
New member
Ha, thanks
However, my suggestion in any endeavor would be to take an argument on it's merits, and not simply on authority. Granted, credentials can count for something, but even the most respected person in their field can be wrong. Hence, arguments should stand on their merits 
Mykel Obvious
New member
<a href=showthread.php?s=&postid=13271545#post13271545 target=_blank>Originally posted</a> by MCsaxmaster
Ha, thanks
+1... just look at some of the experts when it comes to what temp you should keep your tank or on whether or not you should run a DSB... just short of fist fights in some cases
(and several of these guys have PhDs)
MCsaxmaster
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<a href=showthread.php?s=&postid=13271703#post13271703 target=_blank>Originally posted</a> by Mykel Obvious
+1... just look at some of the experts when it comes to what temp you should keep your tank or on whether or not you should run a DSB... just short of fist fights in some cases
Ha, most of the PhD.s I know of that do weigh in on those aspects tend to more-or-less agree on these points.
...as for those that claim to have PhD.s when in fact they don't...no comment
cnaegler
New member
<a href=showthread.php?s=&postid=13271545#post13271545 target=_blank>Originally posted</a> by MCsaxmaster
Ha, thanks
I agree 100%. However, when someone else who doesn't have intricate knowledge of such things wants to challenge someone who does, i find it a waste of time. You have the credentials, because for years, you've studied the intricacies of these things. You've lived it in detail. Does that mean you can't be wrong? Sure you can, you're only human, but you're WAY more qualified than most on such things. It would be different if another marine biologist were taking the other side of this discussion, but it's not.
I mean no disrespect to anyone, we're all just trying to get to the root of it, but i'll take your word on these things over others' any day. You could be wrong but i'd bet it's few and far between.
ChrisKirkland
Reef and Coral Fanatic
8-9 for me.
gavinbree
New member
I'm not sure what Crown of thorns has to do with anything, they have to eat and it just so happens that they are designed to keep coral from becoming too abundant, sure they can get to plague proportions but its just another aspect of nature.
As for the other natural occurrences you mention, yes you are right, but nature isn't only there to keep coral happy, otherwise we wouldn't be here.
I have no argument that the ocean isn't ideal, but coral have adapted to the chemistry of the sea which should be good enough.
When I said thousands in my previous post I didn't mean just one, I meant many thousands, which you probably guessed at, as you mentioned the ocean has seen a few changes over that time.
If there have been so many studies that claim that high Alk is good for coral in low nutrient conditions then why is it that we aren't all striving for higher alk conditions ?
The whole high Alk thing is more to do with human impatience and forcing something to grow at a rate which isn't natural, too much of something is generally bad for most organisms, just because it looks to be doing well doesn't mean it actually is, even if studies suggest otherwise.
STN and tissue recession were around long before people started probiotioc aquariums, but it could just be that more people have low nutrient systems now and that high alk is showing a negative effect that wasn't seen before.
I still think that good enough is better than pushing something to the maximum tolerance, without being pedantic and suggesting the addition of a crown of thorns starfish to maintanin what nature intended either, come on nature never intended for these things to be kept in a glass box anyway.
As for the other natural occurrences you mention, yes you are right, but nature isn't only there to keep coral happy, otherwise we wouldn't be here.
I have no argument that the ocean isn't ideal, but coral have adapted to the chemistry of the sea which should be good enough.
When I said thousands in my previous post I didn't mean just one, I meant many thousands, which you probably guessed at, as you mentioned the ocean has seen a few changes over that time.
If there have been so many studies that claim that high Alk is good for coral in low nutrient conditions then why is it that we aren't all striving for higher alk conditions ?
The whole high Alk thing is more to do with human impatience and forcing something to grow at a rate which isn't natural, too much of something is generally bad for most organisms, just because it looks to be doing well doesn't mean it actually is, even if studies suggest otherwise.
STN and tissue recession were around long before people started probiotioc aquariums, but it could just be that more people have low nutrient systems now and that high alk is showing a negative effect that wasn't seen before.
I still think that good enough is better than pushing something to the maximum tolerance, without being pedantic and suggesting the addition of a crown of thorns starfish to maintanin what nature intended either, come on nature never intended for these things to be kept in a glass box anyway.
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JER-Z
New member
FWIW, I have experienced "alk burn" w/ 12 dkh in a NON pro-biotic tank. Nutrients were low and the alk slowly rose up to 12 dkh using a Litermeter III. I got lazy and didn't test dkh after adjusting my dosage to compensate for an increase in demand (stupid mistake).
When i started noticing the burnt acropora tips a few weeks later i tested and found the 12dkh reading. I observed healing after slowly lowering the dkh back down to NSW levels.
i now keep my dkh @ 8
When i started noticing the burnt acropora tips a few weeks later i tested and found the 12dkh reading. I observed healing after slowly lowering the dkh back down to NSW levels.
i now keep my dkh @ 8
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MCsaxmaster
New member
And the point I intended to make is that the natural condition is not necessarily the most favorable condition, just a tolerable one. Hence, coral reefs tolerate crown of thorn starfish (at least up to plague proportions), though they certainly are not beneficial to the corals.
For part one, agreed, but typically as aquarists we are interested in keeping conditions favorable for the corals
On point two, I’m not sure what you mean to say.
Certainly they can do well enough with natural conditions. However, since one goal is often to grow corals quickly in captivity (for various reasons) it is prudent to consider how to do that.
Okey dokey
Perhaps because most people aren’t familiar with the pertinent literature? Besides that, it beats me.
So, we are to assume that something unnatural is inherently harmful even when the data demonstrate otherwise? Should we all have COTS in our tanks?
Yes, tissue death in corals has occurred for as long as they have. Many stressors can cause tissue recession. There are plenty of systems that maintain low nutrient levels and high alkalinity and have no problems with tissue recession. In fact, the corals grow plenty fast more often than not.
You declare that you think what is natural in this one, particular aspect of husbandry is better than something unnatural: why? Why is it important to follow nature closely in this one aspect, and not in countless others? Why toss out the available evidence that really can inform our decision?
Certainly agreed that nature never intended corals to be kept in aquaria though: nature does not “intend†anything, nature simply is
Chris
MCsaxmaster
New member
But consider: when you changed your dosing scheme, many things changed, not just the alkalinity. How do you know that the change in alkalinity had anything to do with the changes you observed, and not any of the many other parameters that happen to change at the same time?
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