Alkalinity experiment

[jlehigh]

Hey crew,

I re-read the Oct of 04 advanced aquarist article by Dan Riddle titled:
"Elevated Nutrient and 'Trace Element' Concentrations in Reef Aquaria, Preliminary Findings: Their Effects on Zooxanthellae of Porites lobata"

I was particularly interested in the article because I have a few colonies very gradually turning from brown to purples and I witnessed a slight recession in the purpling starting 2 weeks ago.

In have since tweaked the skimmer with positive results and also changed my feeding.

The article suggests elevating Alk to higher than natural seawater levels adjusting for the higher level of P in our closed systems. The idea is that raising Alk raises the bicarbonate levels and assists in growth and nutrient intake the coral animal receives versus the Zoox even with lower calcium levels. (Read the article for a better explanation)

SO! Time for an anecdotal experiment with few parallels!!
This is a timely read for me because my alk is up to 9dkh and my calcium is down to 330ppm. I am going to take some pictures this evening of two acropora colonies battling to color and grow. I will maintain the current calcium levels while raising the Alk another 2 or so parts higher. I will take a picture every three days over the course of 4-6 weeks and see what sort of changes occur in the color and growth.

I will go ahead and post a few pics of the colonies from 3/21/05
(wow just realized I have had good growth in Acro1 the past few months)

More pics later..

 

[DonW]

Why leave the ca at 330 instead of bringing it up to 380 or so.

Don

 

[jlehigh]

It's enables me to check two things:
Can I achieve "good" growth at lower CA levels when Alk with Alk elevated

Will coloration improve at higher Alk levels (more coral pigment, less Zoox)

Edit: the CA level is just relevant to the first item

 

[mojoreef]

Jleghigh your still going to need to have the calcium at, at least natural levels. Carbonate draws out the calcium from the corals cells and deposits it on the skeliton. If you dont have the calcium thier the carbonate can do that efficently. So your on the right track but the calcium should be at least normal and then jack the alk a bit to do what you are looking to do.
On the coloration again your on the right track, but more impportant than that is the nutrient levels.


good post

Mike

 

[jlehigh]

Thanks Mike!

I was working off the following:
"Orthophosphate is generally considered detrimental to the calcification process (Simkiss, 1964). However, Simkiss also demonstrated that high levels of bicarbonate, relative to phosphate, could overcome the inhibitory effects of phosphorus (even when calcium concentrations were relatively low)."

To me this could mean any slow down in growth phosphate may cause can also be possitively impacted by higher bicarbonate levels even with "relatively low" calcium levels. I still need to find out what relatively low is...

 

[esmith]

Thi is going ot be very interesting, can't wait to see the outcome.

I have a hard time keeping my alkalinity up, it usually runs around 4.6 - 5.3 dkh with the calcium ~380. What do you do to drive up the alkalinity, besides adding sodium bicarbonate?

-Eliyah

 

[jlehigh]

Assuming there is any value in the approach beginning with a lower calcium level it would also make sense to extend the test period and designate the second half of the timeframe for a normal CA level.

esmith: You got it, Baking soda and baking powder. The powder is the kicker. I put in 1 part baking powder to 10 parts baking soda. I experienced much more efficient Alk increases when adding the ity bit of powder..

A question for anyone:
I am going to wing the coloration change measurment and use my eyes while also ensuring the time the pics are taken and setting on the camera are the same.
BUT! To effectively measure growth without removing the Corals will be tricky. Does anyone have a good reference to a practice use for more accurate measurments?

 

[DonW]

Pics next to a plastic ruler. Steel one fron the kids.

Don

 

[bradreef]

I remember either bomber or boomer on RC saying that the corals will grow no different if you keep you CA at 350. They cant absorb more CA if it is higher than that. I think it was bomber.

 

[jlehigh]

Yea the ruler will more than likely be the method and I will try to pick several reference points on the coral.

Brad: If that were the case it would make sense to try and keep it a little higher to account for any dips that occure from time to time and not miss out on any growth

 

[mojoreef]

"Orthophosphate is generally considered detrimental to the calcification process (Simkiss, 1964). Yes phosphate ions will pair with calcium and look to percipatate to a seed surface, so then the calcium wont be available for the corals to use.

However, Simkiss also demonstrated that high levels of bicarbonate, relative to phosphate, could overcome the inhibitory effects of phosphorus

Sure hope that the carboante ion out competes the Phosphate ions in trying to bond to the calcium ions. you could try this in the tank, but I dought its going to happen in the corals. (they control the process to well and have a P pump, zoox everywhere). Look to the side effects of this my friend and how will it skew your over all water chemistry. Make sure the gain is worth the try.
Corals dont absorb calcium. calcium is present with in the corals cell structures at the same degree that it is in the water that surrounds them. Cacium with in the cell will inhibit that cell from spliting (thus inhibats the corals from crowing tissue wise) in order to combat that the cells (though the use of a pump) move the calcium ions to the membrane of the cell. Once thier the calcium ion is drawn out by the carbonate ion that is flowing between the cells(tissue) and the skeliton. Once the calcium and carbonate ion pair they need a seed surface to percipatate to, thus the skeliton. So with very low calcium thier is not going to be as much cal ions to draw out of the cell, thus less will be deposited.

On the coloration: most all color pigments with in the corals are genetically encoded. All are enhanced by amino acids supplied from with in and taken from bacteria and such. The color that comes to dominance will happen because of the color temp (bulb) that you are using and how it bombards the coral. To enhance the coloration you are looking to keep your zoox population down, this will allow the pigments to show through (as they are below the zoox), to do this you need to provide proper lighting and a low nutrient load to the tank.

mike

 

[jlehigh]

Okay Mike, you've got me thinking, scared and excited all at the same time. lol

I understand the impact Zoox populations have on what our corals look like to us, as well as how varying Kelvin levels influence the appearance of the coral pigment. I just saw the article suggesting a higher than normal Alk level could impact the Zoox and growth.

What I am seeing is a narrowing of the scope of my experiment and the expected results. In a sense you are also helping me to identify influencers as well.

My calcium level is already on the low side so that issue will only get better from this point. (btw: The decline occured when I tried a different Kalk product for a month, though I'm sure a growing ca demand was there too )

Edit: So say I raise the CA to normal levels, and perform the same excercise of elevating ALK to 12DKH.

Reflecting back to the Warner presenation on water chemistry and the bucket anlalogy helping us to understand when you raise one component then another will decrease because their is maximum threshold in which all the elements in saltwater can reach. So when Calcium goes through the roof, Magnesium and Alk tends to drop..

I'll go look at some Alk articles to identify impacts. hehehe I see this turnign in to another Alk 101! lol

 

[mojoreef]

So say I raise the CA to normal levels, and perform the same excercise of elevating ALK to 12DKH

BINGO!!!!!! we have a winner :idea:

So when Calcium goes through the roof, Magnesium and Alk tends to drop..

calcium up =alk down and mag up
alkup = cal down and mag down

Thats why its tricky to play with the checmistry balance, not only is everything inter related but all the things in SW are used to and have adapted to these levels (ex: they know what to do when the levels ar balanced).
So if you run you water at a salinity of 1.026-7 then cal at 420 and alk at 8-9dkh. Jacking up the alk a bit to 10 to 12 is not going to make a big impact on the balance and as referenced above will help with removing calcium from the corals cells so it can grow


Mike

 

[jlehigh]

Gotchya, and thank you for the balancing correction. Off to get the Kalk I know works best in my tank and organize my test

 

[kevinpo]

esmith: You got it, Baking soda and baking powder. The powder is the kicker. I put in 1 part baking powder to 10 parts baking soda

It should be washing soda (sodium carbonate) not baking powder. Baking powder is normally made of three different parts:

An acid
A base
A filler of some sort
For example, baking soda (a base), cream of tartar (an acid) and corn starch (the filler) are three common ingredients. These are not appropriate for your reef :shock:


Sodium bicarbonate and sodium carbonate can be added at a 6:1 ratio to increase alkalinity without raising PH. If you just want to raise PH add sodium carbonate by itself. Be careful though it is quite powerful.

Regards,
Kevin

 

[The Apprentice]

Thanks for posting this Kevin Is sodium carbonate the main Ingredient that Kent Marine Superbuffer-dKH uses to raise the ph?

It should be washing soda (sodium carbonate) not baking powder. Baking powder is normally made of three different parts:

An acid
A base
A filler of some sort
For example, baking soda (a base), cream of tartar (an acid) and corn starch (the filler) are three common ingredients. These are not appropriate for your reef :shock:


Sodium bicarbonate and sodium carbonate can be added at a 6:1 ratio to increase alkalinity without raising PH. If you just want to raise PH add sodium carbonate by itself. Be careful though it is quite powerful.

Regards,
Kevin

 

[cheeks69]

Charles Delbeek:

The only thing that I know has been scientifically shown regarding alkalinity in closed systems is that increasing alkalinity will result in continued/increased coral growth under high nitrate and phosphate levels. It helps to explain why so many people can grow corals in their home aquaria despite having 100X natural levels of nitrogen in their system.

The problem I have with that is, increasing coral growth often results in much lower density skeletons that can be easily crushed to dust in your fingers.

http://www.reefs.org/phpBB2/viewtopic.php?t=35909&postdays=0&postorder=asc&start=0

 

[jlehigh]

Thank you for the correction Kevinpo

Good info Cheeks: I have so much flow in my tank most of my SPS are very thick branched, I cant imagine them being brittle. Given this will be an "experiment" and only performed for a short period of time I do not see any significant long term issues.

So first thing is first: I need to get my CA levels up just around 100ppm. I will be turning up the evaporation rate on my tank by setting my fan on full time and keeping my auto 35Gal top-off container full with Kalk rich water.

Raising the levels will take some time so this will delay the actual experiment, but I will post updates as soon as I have some.

Tonight's tests show Alk - 7.8Dkh and CA - 320ppm

 

[Katchupoy]

any updates?

 

[jlehigh]

I am still raising my calcium level and will post an update once the experiment is underway.