Why does my tank use so much ALK and everything else is stable

[epleeds]

I have been dosing 2-part recently, but really only half of the 2 part. My calcium is stable at 450, my mag is 1380, ph is 8.2 and everything else is undetectable. My issue is that I am going thru 40ml a day of ALK and nothing else. to keep it around 8.5

 

Is this normal??

 

thanks..

[CHUBAKAH]

is/was your live rock real meaning it came from the ocean, or was it one of these new dry rocks you get from like Marco rocks? If it is one of these man made types then yes it's normal for a while. If it was a real live rock then no that's a little odd.

[flowerseller]

That's an interesting theory that I've not heard.

With arragonite live sand and natural lime/arragonite based live rock, I find I still need a calcium reactor to keep up with the ALK demand.

[epleeds]

my tank has been up and running in its current state for 4+ years. the rock is older than that and came from another tank I had set up. I have no idea why my ALK consumption is what it is and everything else is doing ok.

 

anyone else have this issue?

 

thanks

[flowerseller]

All aquariums containing actively growing sps will notice and increased use ALK.

Some are able to maintain it by frequent w/c while others will even need to suppliment a Ca reactors use.

[flowerseller]

FYI,

Even tanks that are dominated by only or mostly "soft corals" will use ALK.

This is because the spicules, the little rice looking stuff in the soft corals, are calcium based and are used to give them structure and rigidity.

The more loaded or larger sized pieces can have an ALK demand rivaling an sps tank.

[Neal]

I have been wondering the same thing. I have an SPS dominated tank and i seem to use a ton of Alk. My tank has been up and running for 4-5 years with the same live rock. My calcium is at 430 to 440 and my Mag is in normal parameters.

 

It has always seemed to me that corals suck in more calcium than Alk. Am I wrong?

 

Thanks,

 

Neal

[sachabballi reef]

i have the exact same issue lately and am struggling to dial in the 2 part to keep the alk high enough...it seems like everytime I think I have it I check a day or so later and its back down to 7....very frustrating, however we recently moved into NOVA and had to start the tank over again so I have a complete tank full of sps frags and they must just be using it up like mad even though everything else is stable....glad to hear I am not alone...misery DOES love company

[Sharkey18]

My tank is the same. I use 2 to 3 times more alk than calcium. I never worry about it.

 

In my 120 I dose about 600 mls per week of alk.

 

Laura

[epleeds]

In my 120 I dose about 600 mls per week of alk.

 

laura

 

600ml that is a lot. I am running 280ml a week (40 per day)...

[ctenophore]

If you aren't seeing calcium drop along with alkalinity, then your calcium test kit is probably not accurate. They are used in equal proportions by calcifying organisms. Adding 600 ml/week of alkalinity solution and zero calcium will cause ion imbalance over time.

[CHUBAKAH]

That's an interesting theory that I've not heard.

Can't say that ever again. HA

 

That is actually based on a system I built a couple of years ago where the guy had to dose 75 ML of [brand escapes me] a day to keep the ALK at 8. As the rock finally got to where it looked cured, and covered he was able to back off the dosing.

 

 

 

[ctenophore]

Marco rock isn't man made, it's just dried up chunks of old seabed. It definitely came from the ocean at some point. As to why it consumes alkalinity, maybe the initial bloom of microflora were calcifiers? I don't know why dry chunks of calcium carbonate would cause alkalinity levels in solution to drop. Maybe ask RHF over on RC chemistry forum?

[CHUBAKAH]

I did not know Marco was not man made. Bad reference on my part, and was not what was used either.

Strike that comment.

[sen5241b]

I have the same problem. What many people don't know is that coralline will suck carbonates (alk) out of the water. I'll bet you have a lot of coralline.

[BowieReefer84]

I have the same problem. What many people don't know is that coralline will suck carbonates (alk) out of the water. I'll bet you have a lot of coralline.

 

Hmm.. Coralline uses alk more than calcium? I did not know this. I thought they were always used proportionately, and one goes down when the other rises or vice versa due to over supplmentation of one versus the other? I am confused. Someone explain for me please. THANKS. I am not even sure my questions make sense...

[Der ABT]

reefkeeping alk CA

 

here is a good article about the two. I would agree with justin that your CA test kit may be off, try either getting a new one or take it to a store/friend and see what theirs says.

 

when he says equal proportions its not 1 to 1, it may be like 2 to 1 or even more but the proportion should be constant. Reefkeeping has some good articles on alkalinty just google them or search their site and get reading.

Edited August 17, 2010 by Der ABT