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View Full Version : Is there a formula for calculating Ca/alk balance? Developing an iPhone program


Carissa
07/05/2010, 11:47 AM
I am working on a program for the iPhone that will be an all-in-one handy tracker and tool for the aquarist. I would like to incorporate a calculator for figuring out the proper Ca/alkalinity balance - i.e. if your Ca is x ppm, your KH should be x degrees, or vice versa. But I can't find the formula for calculating this, all I can find is the ratio of consumption which is not what I'm looking for. There must be a formula for finding the balanced KH for Ca or vice versa, does anyone know?

Also if there are any ideas for other calculators that reef keepers would use, or parameters that they would want to log, I'm open to suggestions. I am very experienced with freshwater but not quite so much with reefkeeping other than the basics of a fowlr. I don't want to bother with anything really obscure to overcomplicate it for newbies, but anything that would be relatively useful (i.e. up to about the 80th percentile of reefkeepers.... the 81st to 100th percentile can write their own program :) .

Thanks in advance!
Carissa

HighlandReefer
07/05/2010, 11:52 AM
There really is no proper alkalinity to calcium balance ratio for reef tanks. Alk and calcium can be at any level the hobbyist prefers as long as it is between the recommend levels:

alk: 7-11 dKH
calcium: 385-450 ppm

FWIW, many hobbyists keep their alk levels higher then is recommended without negative signs, except perhaps more calcium carbonate precipitation at levels above 11 dKH. Many salt mixes and hobbyists keep their calcium levels above 500 ppm without problems. :)

HighlandReefer
07/05/2010, 11:53 AM
Have you seen JDiek's calculator yet?

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

HighlandReefer
07/05/2010, 12:07 PM
The idea of balanced alk and calcium dosing comes from adding the two supplements to maintain the level you desire. Once the calcium and alk levels are where you want them, then adding the balanced amount of calcium and alk that the occupants use them (1 meq/L of alk for every 20 ppm calcium) will maintain the desired levels. However, salt mixes with high calcium and alk levels will cause problems and require you to make some adjustments to the amount you dose, especially the high calcium salt mixes due to the fact that a lot less calcium is used per 1 dkH of alk. :)

Carissa
07/05/2010, 02:56 PM
Have you seen JDiek's calculator yet?

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

I guess what I'm looking for is the formula to make a calculator like that. What I mean is, when you enter the desired Ca or alkalinity, it the tells you what the balanced opposite component is. Like if dKH is 8, it tells you balanced Ca is 417ppm. Where does that number come from? Isn't it possible to have both numbers fall within the acceptable range, but still be out of balance? Or not?

bertoni
07/05/2010, 03:42 PM
Those numbers basically just reflect the author's personal choice as to his favorite alkalinity and calcium levels, and they don't mean anything in particular. Trying to achieve some sort of balance like that isn't useful, and it can be rather time-consuming at best.

hounddog01
07/05/2010, 04:09 PM
I use randy's calculator on my iPhone it works nicely and will show you where the balance of cal and alk should be.

gabrielt
07/05/2010, 04:59 PM
You should read "The Reef Aquarium Vol. 3" by Julian Sprung and J. Charles Delbeek for a deeper knowledge on the subject.

Boomer
07/05/2010, 07:45 PM
There is also this from jd




A new calculator for cell phones:

http://reef.diesyst.com/cf/chemcalccf.html




I use randy's calculator on my iPhone

That is not Randy's but jd's :)



You should read "The Reef Aquarium Vol. 3" by Julian Sprung and J. Charles Delbeek for a deeper knowledge on the subject.

I do not think so :). These two are a couple of my good friends, I helped them on the updated version to be out when ever and they got most of their info from reading theses and the ref in the book show that also. I will add it is an excellent book and all reefers should have one. It would solve allot of the questions asked here and the same for Randy's articles:)

For a deeper knowledge on the subject


http://archive.reefcentral.com/forums/showthread.php?s=&threadid=102605

Boomer
07/05/2010, 08:03 PM
I guess what I'm looking for is the formula to make a calculator like that

It is all on jd's web page. You need to know algorithms to make such a unit.

Source;

Go here http://home.comcast.net/~jdieck1/chemcalc.html

Then right click somewhere on that page and choose "View Source page"

TheH
07/05/2010, 09:51 PM
You can PM JDieck here on RC for the algorithms and (most importantly) the concentrations of the respective brands, but as bertoni mentioned achieving "balanced" calcium and alkalinity doesn't have any benefit.

chuckreef
07/06/2010, 10:36 AM
Although I don't see what the purpose is, you could bound the acceptable ranges for alkalinty and calcium and use the ratio (i.e., the slope) of 10 ppm Ca for each 0.5 meq/L as the formula for within that range. Randy's excellent articles contain graphs that depict both the relationship and the target range.

Carissa
07/06/2010, 11:06 AM
Ok thanks for all the replies. I guess a formula for this isn't all that useful anyway so I'm going to remove it from my program design. Mainly what I am making is a tank log, I was just going to include some calculators for a handy reference. I already have lots of calculators planned for the freshwater side of it but not too much for the saltwater arena.

Carissa
07/06/2010, 11:08 AM
I guess what I'm looking for is the formula to make a calculator like that

It is all on jd's web page. You need to know algorithms to make such a unit.

Source;

Go here http://home.comcast.net/~jdieck1/chemcalc.html

Then right click somewhere on that page and choose "View Source page"

Right on I do see that! I checked the source earlier when I was looking around but I think I must have done it on another site, since it didn't let me see any of the code.

TheH
07/06/2010, 11:24 AM
What kind of calculators do freshwater people need? Can't be as much as saltwater...