alkalinity questions

I can't seem to keep my alkalinity up. I dose it often and it's always at 6. Does anyone know what might cause this and what products might help stabilize it?
 
Calcium and alkalinity are relative to each other. What is you Calcium at?
 
I have to dose Alk DAILY,
I use a shot glass per day of the RHF Alk mix.
And it still needs adjustment about once a week.
I have to dose CA about 2 per week
And MG once per week
I think I need some dosing pumps or something!!!

And I also have a 30G tank (With a 20G sump and 10G fuge)

It's very normal for alk to get sucked down.
Do everything in your power to keep it up at least at 8.0 or higher.

I have a bunch of small SPS's and a nice 4" clam. They keep tugging at my alk all day every day.

What brand of stuff are you dosing and how much / how often?
 
Clams do drain your alk and calcium, but they really help with nitrates as well.
 
5 clams, 3 months, still relatively stable. Dose 5ml Kent pro buffer dKH every other week, and 15-25 grains Kent turbo calcium on roughly the same schedule. pH: 8.2, 8.2, 8.2, 8.0 (dose), 8.2... Calcium: 460, 440,440, 440, 420, 400, 380 (dose), 460... Softies and limited LPS.

What acids or acid producing variables are in (or entering) your tank? Besides clams (Clams. I like clams. Say it with me: "Clams.") -- What other consumers of acids are present?
 
Alk dropping is also related to bioload given the acidity of things like fish poop, food, etc. Alkalinity can easily be controlled by dosing with baking soda (not powder - SODA!). Take a bit of the Arm and Hammer, dissolve it in water (check out twopartsolution.com for exact levels) and add a little at a time to get the results you are looking for. Do NOT overdose the stuff too quickly, many corals do not react well to large shifts in alk or PH - a little goes a long way.
 
<a href=showthread.php?s=&postid=9891732#post9891732 target=_blank>Originally posted</a> by Marko9
Calcium and alkalinity are relative to each other. What is you Calcium at?

Clams and SPS along with corraline algae are one of the largest sources of Alk/Ca uptake. Alk/Ca are used in calcification, which is the reason for the daily depletion of it.

With standard test kits, it will appear your alk is consumed daily in large quantities, but your Ca remains stable.

This is not the case. The resolution of the tests do not show the Ca droping. Its easier to see a 10% of 1,000,000 drop rather than 10% of 1000. In reality they are both being consumed under ideal conditions and need to be replenished daily to keep alk/ca balance. However, if one is out of balance one can adjust the ratio to reobtain the needed levels.

There is only so much room in the water for dissolved ions. When the alk or Ca gets too high, it limits the other amount. This is what Mark and I suspect what is going on.



Read these, yes its alot, but I read them when first starting out also...............and they explain all you need to know.

Calcium and Alkalinity

A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH
http://reefkeeping.com/issues/2006-06/rhf/index.php

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php

A Homemade Two-Part Calcium and Alkalinity Additive System
http://www.advancedaquarist.com/iss...il2004/chem.htm

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

Electronic Calcium Monitoring
http://reefkeeping.com/issues/2005-04/rhf/index.htm

Purity of Calcium Chloride
http://www.advancedaquarist.com/issues/mar2004/chem.htm

Calcium and Alkalinity Balance Issues
http://reefkeeping.com/issues/2002-...ature/index.htm

Calcium Carbonate as a Supplement (Aragamight; Liquid Reactor)
http://www.advancedaquarist.com/iss...ly2002/chem.htm

The Relationship Between Alkalinity and pH.
http://www.advancedaquarist.com/issues/may2002/chem.htm

The Chemical & Biochemical Mechanisms of Calcification in Corals
http://www.advancedaquarist.com/issues/apr2002/chem.htm

Calcium
http://www.advancedaquarist.com/2002/3/chemistry

What is Alkalinity
http://www.advancedaquarist.com/2002/2/chemistry
 
Last edited:
Thanks Doug- Yes. My question was a probing question that could help us diagnose the true need ;)
 
A couple of other things I saw but didn't touch on in the first cuz it was late:

On low demand tanks without LPS, clams, SPS......you can usually rely on regular WCs to keep you params within range. (this is what I do on my nano) As you add calcareous livestock, the demand for alk and ca will increase over time as you do.

I use liquid Ca such as Kent Turbo Ca and Powdered buffers to start a tank and get the Alk and Ca within acceptable ranges. These are super concentrated and can be used for supplementation, but are easy to overdose, (I have done it many times myself), and hard to control a static level. 2-parts are designed for DAILY replenishment and if used properly one can dose by hand and keep a static, in balance Alk/Ca ratio indefinatly. To do so, test the alk daily before dosing and adjust accordingly. Test Ca weekly or monthly to ensure balance.

Ph isn't the best method of telling when to add your alk, alkalinity tests are.....I suggest Salifert. Commonly the Ph tests are not accurate and the resolution is difficult at best. Regardless, Ph shift is the metric that alkalinity controls. Once your ph moves.....you have already moved a great deal in the Alk range. Alkalinity in a nutshell is a "shock absorber on a coilspring" for Ph. Too low and your Ph moves with ease, too high and it could be set at the wrong level, much like if your shocks are too stiff or worn out on your car. In addition, ph fluctuates daily based on fish respiration and the amount of CO2 in the water, so if you do test Ph regularly do it at the same time.

The best thing to do is pick a Alk value you want (most shoot for 9-10dkh) and hold it there every day......the more stable the less stress on the coral and in the end fast growth. In a smaller tank these things happen twice as fast than in a larger tank.

I currently dose B-Ionic on a Sentry doser. Before I switched to the doser I was hand dosing about 60mls daily.
 
Last edited:
wow! tons of info! To answer some of the questions I have been asked, I use wellfish brand dkh test kits, I know they suck and I should use salifert but their so expensive. To dose I use seachem liquid alkalinity and seachem powdered alk. buffer. My calcium is usually at 440. As far as calcareous livestock I have tons of liverock and mostly lps and softies. All wrapped up in a 30g cube.
 
I'll throw in one more opinion for the heck of it...
My tank sucks up a lot of calcium and carbonates since I have 8 clams, including two gigas clams. Those things use Alk and Ca like crazy! I also run a calcium reactor. I can keep my calcium between 400-420ppm but I have to add carbonates on a regular basis to keep it around 10-12dKH. pH ranges from 7.9 to 8.2. I have been using Seachem's "Reef Builder" and go through about 20 teaspoons a week of it on a 300gal tank.

Anyway, lots of great info in this thread!

PS - if you are using Seachem's products, go to their website. They have a really good online calculator for each of their additives that calculates just how much you need to add for a given volume and concentration.
 
Back
Top