msuzuki126
New member
What negative effect would a dKH of about 15 have on SPS? Do any of you have SPS systems with high alk?
Thanks,
Matt
Thanks,
Matt
High alk effect on SPS?
- Thread starter msuzuki126
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msuzuki126
New member
Thanks Yinger, anyone else?
msuzuki126
New member
Thanks for the comments.
Amphiprion
Premium Member
I noticed a dullness in and decalcification of axial corallites when my alkalinity spiked to about 8 meq/L due to reading a bad test kit and me adding more buffer.
waterfaller1
New member
I run my alk at 11.2 DKH w/ CA at 450, MG at 1350..my acros and all my corals do great.
northbay-reefer
Active member
Its because your corals are growing and are using up your alk faster than you can add, in this case you will need to add more alk.
High alk will definitly cause your corals to stress. I keep mine at about 7-8 range
MiddletonMark
Premium Member
And I've had some depressing basal recession when my Alk drops below 6.5.
I'd aim for the 8-9 dKh range. Enough to avoid problematic dips, low enough to avoid pH and other issues of high Alk.
MiddletonMark
Premium Member
Wow, I've never had a problem between about 7 - 10 dKh.
Then again, my tank isn't every tank. Obviously
Then again, my tank isn't every tank. Obviously
MJAnderson
Premium Member
I'm surprised people keep theirs so low. After reading this excerpt from Randy's Chemistry overview, I have been keeping mine around 10 dKH
"Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in Porites porites.4 In this case, doubling the bicarbonate concentration resulted in a doubling of the calcification rate. Uptake of bicarbonate can apparently become rate limiting in many corals.5 This may be partly due to the fact that both photosynthesis and calcification are competing for bicarbonate, and that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration)."
"Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which has shown that adding bicarbonate to seawater increases the rate of calcification in Porites porites.4 In this case, doubling the bicarbonate concentration resulted in a doubling of the calcification rate. Uptake of bicarbonate can apparently become rate limiting in many corals.5 This may be partly due to the fact that both photosynthesis and calcification are competing for bicarbonate, and that the external bicarbonate concentration is not large to begin with (relative to, for example, the calcium concentration)."
<a href=showthread.php?s=&postid=9066102#post9066102 target=_blank>Originally posted</a> by MiddletonMark
Wow, I've never had a problem between about 7 - 10 dKh.
Then again, my tank isn't every tank. Obviously
I use to keep dKH at 9-10. Then switched to Zeovit. 6-8 dKH is recommended. Over 8 corals get stressed.
JB NY
Active member
In all honesty I think you are fine with your alk between 8-10. I prefer to keep it around 8. I think when you get to levels like 12-14 you start to push it. Meaning I do not think that the coral will suddenly RTN on you, but I do think that if something happens in the tank the coral is more susceptible to problems when you have a higher alk. IME I have found that acroporids are a little more forgiving when you have a lower alk.
As far as Randy's comments. He is surmising that higher amounts of bicarbonate would be helpful in getting more growth from corals. But Randy does not keep SPS, so you need to take that advice with a grain of salt. Also, I fully believe that you can get a little more growth and in some cases a little more color out of the coral with high alk, but again I feel that the risk to the acro more than outweighs the benefit you might see.
HTH
As far as Randy's comments. He is surmising that higher amounts of bicarbonate would be helpful in getting more growth from corals. But Randy does not keep SPS, so you need to take that advice with a grain of salt. Also, I fully believe that you can get a little more growth and in some cases a little more color out of the coral with high alk, but again I feel that the risk to the acro more than outweighs the benefit you might see.
HTH
zuzecawi
Member
Hmm... while going through the Ultimate Marine Aquariums, I noticed a few reefers with sps who attributed success to high alk levels.
Personally, I have noticed that my corals start to bleach if they fall below 9 dkh, and I get the best color and polyp extension at around 12-14 dkh. I try not to push it higher than 14, but I've had it go as high as 17 dkh with no ill effects to the corals, but it did make my DSB turn into a slaggy batch of rocks. I haven't had that happen for over a year now, but I do maintain my dkh around 12 on a steady basis. I also keep a high calcium level though, around 460-480. And lower temps. (74-78 seasonally). I have had several brown corals color up and turn green, pink, purple, red, etc, usually within a matter of a few weeks. Then again, I've also had no luck with the cream colored corals with blue or purple polyps, almost all of them lost the polyp color, although they grow vigorously and have great extension and color otherwise. Currently a few are coloring back out their polyps, (purple polyped cream montipora namely) but I'm not holding my breath. Seems to me the darker colored corals do better in my tank anyways. Might just be the lighting I have vs. the fish store's super actinic scheme though.
Personally, I have noticed that my corals start to bleach if they fall below 9 dkh, and I get the best color and polyp extension at around 12-14 dkh. I try not to push it higher than 14, but I've had it go as high as 17 dkh with no ill effects to the corals, but it did make my DSB turn into a slaggy batch of rocks. I haven't had that happen for over a year now, but I do maintain my dkh around 12 on a steady basis. I also keep a high calcium level though, around 460-480. And lower temps. (74-78 seasonally). I have had several brown corals color up and turn green, pink, purple, red, etc, usually within a matter of a few weeks. Then again, I've also had no luck with the cream colored corals with blue or purple polyps, almost all of them lost the polyp color, although they grow vigorously and have great extension and color otherwise. Currently a few are coloring back out their polyps, (purple polyped cream montipora namely) but I'm not holding my breath. Seems to me the darker colored corals do better in my tank anyways. Might just be the lighting I have vs. the fish store's super actinic scheme though.
