Low dKH =bad color/poor polyp extension?

[galleon]

Is anyone convinced that these two symptoms can be a consequence of verified low alkalinity?

[Acronic]

how low are we talking here? Ive run 6.5dkh in the past with no issues...

[Alex T.]

Natural seawater has lower dKH than almost all captive aquariums and artificial salt mixes with no ill effects. I'd look somewhere else to see what could be causing this.

[karsseboom]

No it dose not, stability of dkh has an impact on Health.

[Acronic]

I just recently raised the dkh in my tank from 7.5 to 8 and Im seeing better growth, color is the same though.

[Alex T.]

No it dose not, stability of dkh has an impact on Health.

Is this in response to my post? I never said anything about stability at all. In fact, I don't think the OP said anything regarding stability...only if low alkalinity effected color and polyp extension.

[karsseboom]

Is this in response to my post? I never said anything about stability at all. In fact, I don't think the OP said anything regarding stability...only if low alkalinity effected color and polyp extension.

To answer his question...no low alk does not effect polyp extension or color. I was not referring to what you posted. I was making a general statement.

6.5-12 is an accepted range of success.

[xenon]

I just recently raised the dkh in my tank from 7.5 to 8 and Im seeing better growth, color is the same though.

Higher alk = faster growth. That's normal.

In ultra low nutrient systems, alk above 8.0 will burn sps tips.

[Allmost]

Natural seawater has lower dKH than almost all captive aquariums and artificial salt mixes with no ill effects. I'd look somewhere else to see what could be causing this.

other way around :) remember, our corals come from the ocean,

so many Reefers, keep their alk higher than normal, in order to give them more room for mistake so the alk can fall more before causing ISsues.


In my system, when alk is low, corals do not take up as much nutritions as they normally would, which means the net nutrition in water is higher, which in turn makes corals loose their glow. that's how Itell when it is low, and of course, burned tips for high alk.

PE.... I am not sure, I always link that with pottasium ...

[karsseboom]

Another thing to point out is polyp extension is not an indication of a healthy Sps.

[blackthunda77]

I dont think low dkh results in poor color and lack of polyp extension, just slow growth.

For me when i usually get browned out corals or no polyps extension its usually high nitrates or phosphates or pests like red bugs or flat worms.

[Acronic]

Higher alk = faster growth. That's normal.



I dont necessarily agree with that. In some tanks that seems to be normal but ive run a set up that had much better results at 6.5dkh where anything more than 7.5 yielded bad results. Much of that may depend on the test kit though and ive used a few different brands.

[karsseboom]

Higher alk = faster growth. That's normal.

In ultra low nutrient systems, alk above 8.0 will burn sps tips.

False higher alk does not mean faster growth.

[xenon]

I dont necessarily agree with that. In some tanks that seems to be normal but ive run a set up that had much better results at 6.5dkh where anything more than 7.5 yielded bad results. Much of that may depend on the test kit though and ive used a few different brands.

I should have added more detail

Faster growth requires more than just higher alk.

You also need higher calcium and magnesium in a balance and also slightly higher PO4/NO3 because when nutrients are too low, you will get tip burn.

That is why you noticed negative results with higher alk. You phosphates and nitrates were too low for optimum growth.

Unfortunately you need to give up coloration if you want faster growth.

[Alex T.]

False higher alk does not mean faster growth.

Actually, Randy has already written an article showing that higher alkalinity actually does increase calcification/growth. I recall him mentioning in the Chemistry forum a few times that this is MO for many frag farmers looking to boost growth.


To quote Randy...

[I]
"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 says that the uptake of bicarbonate can apparently become rate-limiting in the growth of some corals."


The entire article can be found here:

http://reefkeeping.com/issues/2007-04/rhf/index.php#4

[karsseboom]

Actually, Randy has already written an article showing that higher alkalinity actually does increase calcification/growth. I recall him mentioning in the Chemistry forum a few times that this is MO for many frag farmers looking to boost growth.


To quote Randy...

[I]
"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 says that the uptake of bicarbonate can apparently become rate-limiting in the growth of some corals."


The entire article can be found here:

http://reefkeeping.com/issues/2007-04/rhf/index.php#4

Well can't argue with randy but I just don't see how raising your alk would increase growth. I have ran a few different Sps tanks with different methods, running alk high and low and never saw an increase in growth that I could attribute to higher alk.

I would also like to note that some of the most amazing, fastest growing Sps tank in the world are running there alk at 7.

[reefsurfing]

Well can't argue with randy but I just don't see how raising your alk would increase growth. I have ran a few different Sps tanks with different methods, running alk high and low and never saw an increase in growth that I could attribute to higher alk.

I would also like to note that some of the most amazing, fastest growing Sps tank in the world are running there alk at 7.

If you have high alk and your other parameters aren't in balance to support that elevated level it will percipitate out in one way or another. Randy would explain it much better than I ever could. Its like running with a lower set of parameters all around as the excess turn into an unusable form that the corals cant absorb.