Alk drop

[returnofsid]

I have a question about Alk. I have a 29 gallon frag tank that is fairly heavily loaded with SPS frags. It's bare bottom and has a few pieces of live rock in it. I do plan to add more live rock soon. Flow is created with a single Koralia 3 and it has a large CPR Aquafuge on it. No skimmer. I do a 8 gallon water change each week. I test Ca, Alk and Mg once per week, several days after doing water change. I use IO salt and RO/DI water. I dose Randy's 2 part; Ca, Alk and Mg. I drip Kalk for most, but not all of my top off water. My goal numbers are Ca 425, Alk 9 dKH and Mg at 1300.

For the last 3 weeks in a row, when I test, my Ca is down to 380, which isn't so bad, but my Alk is very low...in the 5-6 dKH range. Magnesium has stayed pretty stable. Any idea what could be causing my Alk to drop so quickly and so far? I guess I need to start testing and dosing more often. Could it be because I don't have any live sand to act as a buffer? Any suggestions on how to fix this and keep my Alk and Ca more stable??

 

[jezzeaepi]

Sounds like you have a lot of calcium/alk uptake. Might want to start dripping kalk and/or daily dosing to keep up!

 

[mojoreef]

whats your salinity


mike

 

[returnofsid]

Salinity is 1.025 and stays there. I figured, with all the SPS, that the Ca would drop quickly, although it's not dropping as much as I'd expected. Didn't think my Alk would drop as much though.

 

[mojoreef]

Your alk of around 6 dkh is right in line with 380 cal, specially when you allow for a +/- on the salinity and test kits accuracy. You can increase if you want, but its better to have normal skeliton growth, easier on the coral itself.


Mike

 

[returnofsid]

I guess that makes total sense. I'd never checked the balance numbers at that low so figured my Alk was dropping faster than my Ca. I guess the answer is to test and dose more often...lol.

 

[mojoreef]

Maybe. Remeber calcium inhibits coral growth (sps that is) so you dont want to jack it up to high. It will make them work to hard and thus be a little weaker

Mike

 

[returnofsid]

Wait, Calcium inhibits growth? I thought SPS and LPS needed calcium for calcification of their skeleton? I knew you didn't want calcium too high, but thought you wanted it between 380-450 and a balanced level of Alk.

 

[mojoreef]

Wait, Calcium inhibits growth? I thought SPS and LPS needed calcium for calcification of their skeleton?

Actually they dont want calcium, if they couldnt get rid of it they would not grow.
Ok short and skinny on sps:

The coral (sps) is just the tissues over what we call the skeliton, two cells deep. Corals grow by cell splitting, calcium inhibits the spliting of the cell. Since the coral has SW in it the same as is outside of it. that means that calcium is present in the cells. Corals have (keeping it simple) a calcium pump built into the cell. It pumps the calcium to the wall of the cell, migrates it to the outer surface where the alk in the SW coarsing through it present. The alk binds with the calcium ion and looks for a clean seed surface (skeliton) and then binds as a solid. So look at the skeliton as a dumping ground.

So when you keep your alk and cal at really elevated levels you are making the coral use a larger ammount of its energy budget to do the deed. Since its energy budget is fairly fixed that means its got to take away from something else, like feeding, mucus netting, defence and so on.

make sence


Mike

 

[CarlaW]

Sid, I remember Mike telling me this about 3 years ago, and the story hasn't changed!!!

Mike, it is real nice to have you back around to help explain things to us dummies.

 

[returnofsid]

Okay so Calcium is kind of a "waste product" that, as it's being expelled, forms the skeleton right? But, the corals have to have calcium in order to build the skeleton right? If not, why is it stressed as being so important? I do understand what you mean about it making them work harder to expel it, if it's kept at higher levels than needed. They'd have to expel more of it if it's kept at higher levels. So, I've always thought it was important to keep it around or near 400 but that at levels above 450, it could become stressful to corals. What levels should I be keeping my Ca and Alk at then?

LOL I'm sooo confused now!!!

 

[surf_buddy]

Tagging along... new info for me!

 

[mojoreef]

Okay so Calcium is kind of a "waste product" that, as it's being expelled, forms the skeleton right?

yep

But, the corals have to have calcium in order to build the skeleton right?

The corals have to split thier cells in order to grow. The skeleton is a waste product, they dont need to grow it, it just grows because of the process I discribed.

But, the corals have to have calcium in order to build the skeleton right? If not, why is it stressed as being so important?

Hmm let me through a few quotes at ya. "Hey look t this man I am getting 3/4 of an inch a month" "I'll be fraggin this puppy with in a couple of months" which from time to time are followed by "Bummer man everything was growing so fast and then RTN" "I dont know what happened"

Sid I dont claim to know exactly but I figure if they grow in the wild just fine, its probibly best if we try to keep the level as close as we can to natural. That is unless God is dosing kalk while we arent looking


Mike

 

[Scooterman]

I remember reading somewhere when Anthony was writing about how sps in particular do better with a balanced range of about 380 to no more than 420ppm ca, key balanced & consistency. I also remember Boomer slapping my hand when I was trying to keep higher ca levels un-natural & throwing everything out of balance, had to do lots of water changes & learned to leave things alone not trying for perfect numbers. Can't say I have the fastest growing corals but as hard as it may seem they don't die off either for no apparent reason.

 

[returnofsid]

Okay, that's all making sense. I'm not aiming for fast growth. I'm just wanting healthy corals. I guess I was under the impression that the Ca goal I had of 425 was healthy. Thank you all for your help. I'll keep reading and studying up on this. It would seem that my thinking has been off on all of this for quite some time!!

 

[delemi]

I'd bet that the misconception comes from the proliferation of the Blu Coral Method - which aims at the CA to be 500+

But as I read more about the method I can see how the addition of steriods are required since the elevated CA levels would increase growth, but also stress corals - Given Mojo's education above

Here's a link to the old thread for more reading!
http://www.reeffrontiers.com/forums/showthread.php?t=23289&highlight=blue+coral+method

 

[roscoe]

So with SPS... the skeleton is just a surface area that the SPS skin cells use to reproduce on? So if that is the case how come there are so many different shapes and forms if all it is doing is using the skeleton to reproduce new cells on? I just want to understand a little more about the reproduction of sps becuase I do the very minimal to my tank and have great colors and growth as oppose to other I know that has tried everything under the sun to get their SPS to look better.

 

[Herefishyfishy]

One of the best writeups on Corals. Long but worth the read:

http://oceanservice.noaa.gov/education/kits/corals/coral03_growth.html

 

[mojoreef]

I'd bet that the misconception comes from the proliferation of the Blu Coral Method - which aims at the CA to be 500+

But as I read more about the method I can see how the addition of steriods are required since the elevated CA levels would increase growth, but also stress corals

Raising levels has been around for decades. On the steriods I am not one that buys into it (just never got a good enough explanation on it). Aminos yea they can help, but 95% of those you add end up being bacteria feed anyways, seems expencive to me.

So with SPS... the skeleton is just a surface area that the SPS skin cells use to reproduce on?

The cells reproduce, the skeleton is a byproduct period.

So if that is the case how come there are so many different shapes and forms if all it is doing is using the skeleton to reproduce new cells on?

Oh man your going to make me work here. Ok visualize two layers of cells, so a bunch of aval shapes stuck together. The SPS type/species/so on is already defined (as it comes from a parent colony) so we have a clump of tissue that has its form, but has no skeleton yet. The cells begin to pump out calcium so the can devide. They transfer the calcium ions to thier cell walls (already preform to the species) the ca at the outer wall is attracted to a alk ion (keeping it simple here) which free floats through the coral cells, they bind and then look for a seed surface (kinda like how ca binds with alk and the sticks to your hears/pumps and so on) the seed surface is the skeleton (yes they come with a tiny one) and the two ions come out of solutions and forms a solid. Thus building the skeleton. The skeletons form comes from the corals form.

Thier are all sorts ways to color up corals but thats for another day.


Mike

 

[roscoe]

Thanks Mojo!! I completley understand now!!!!