Nutri-Calculator

Grafalski

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Feb 24, 2006
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I took a look at Nutri-Calc and was wondering about amount of MgSo4.
I have 29 gallon tank and ( 29 - amount of gravel = 23 US gallon), water change 50% every week. The Nutri-calc says I should add 1 tsp of magnesium twice/week - it`s a lot. I started mixing Ro water with tap water and my GH is 6. I don`t add magnesium anymore. If I add 1 tsp of MgSo4
my water hardness will be changed significantly. I`ve got couple plants and fish that prefer soft water.
What do you think? Should I go with Nutri-Calc or add less magnesium or maybe not at all to keep my water soft?
 

quenton

Guru Class Expert
Mar 14, 2006
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Toronto Ontario (Canada?)
Re: Nutri-Calculator

Both Mg and Ca call for a large amount to add the noted ppm's.
For example, ignoring EI for now, to add 10ppm to 29g of water
would require 2 1/4tsp -- that is lots of stuff compared to other
nutrients. For example, for Nitrates, you would add 3/8tsp to the same
water to get 10ppm. So the quantity for Mg is going to look large in
comparison.

The other thing to think about is what your source water has in it.
Mine starts at 8ppm, so I add only a small amount (1/2tsp for 77g of water
3x a week for EI).
 

Grafalski

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Feb 24, 2006
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Re: Nutri-Calculator

OK. What method do you guys use to check Ca or Mg levels in your tanks?

I found this formula online:

Starting with Mg portion of target:
Ca ppm = 4 x Mg ppm
(2.497 x Ca ppm) + (4.119 x Mg ppm) = GH ppm
9.988 Mg ppm + 4.119 Mg ppm = 17.9 ppm
Target Mg ppm = 1.27
Target Ca ppm = 5.08

MgSO4+7H20 dose (note: using 55gal, but you should substract 15-20% for displacement if you are anal):
Target Mg ppm x 3.77L/gal x (mg MgSO4+7H2O4)/mg Mg x Tank gal = MgSO4 mg dose
1.27mg Mg/L x 3.77L/gal x (10.1mg MgSO4+7H2O4)/mg Mg x 55gal = 2660mg MgSO4 =~ 2.7g MgSO4

CaCl2 dose:
Target Ca ppm x 3.77L/gal x mg CaCl2/mg Ca x Tank gal = CaCl2 mg dose
5.08mg Ca/L x 3.77L/gal x 2.77mg CaCl2/mg Ca x 55gal = 2917mg CaCl2 = ~ 2.9g CaCl2


GH = (ppm Ca / 7.2) + (ppm Mg / 4.4)

Can you guys confirm that?
 

quenton

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Mar 14, 2006
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Re: Nutri-Calculator

I don't bother. I may test Ammonia and nitrite once in a while, nitrate maybe, but the test is not very accurate at the levels we deal at.

For Ca and Mg, I get my source water info from the city (If you live in the country and have a well, you can probably get a your county to test it for
Mg and Ca). Then you add what you need to raise it. Mg uptake is not all that great, so you can figure that not much occurs from week to week.

The Nutri-Calc numbers are based on that presumption -- you just add enough to raise the changed water to the level you want and forget about it.
 

Wet

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Re: Nutri-Calculator

Hi Grafalski. Those are my calcs from APC. The Mg and Ca portions of target are correct using my listed assumptions, which checks out using Niko's GH calc and the Fertilator, but apparently said assumptions are incorrect. If you scroll down that thread, Salt breaks it down correctly -- caluclating dGH increase from Ca and Mg ppm is not as simple as previously thought (and over my head). Calculating dose from mass after getting target is correct and the same: the tricky part is knowing exactly how much Ca and Mg are in 1dGH.

To answer your original question, with 6dGH from tap I don't think you have to worry about adding Mg. It is possible that all the GH is made up of Ca, but in applied practice this is unlikely. If your plants are alright, don't worry about it. If you'd like, ask the county (or check their website) for a water quality report to ensure there is Mg available. Likely you already have at least 10ppm Mg.

To answer your question about what I personally do, my tap has the same dGH as yours. In most tanks I just change water weekly. In one tank I mix 50% RO/DI with 50% tap and again don't worry about more Mg. I sometimes add Ca just to do it (with no significant observable difference).

When folks talk about soft water, almost always they are talking about KH, not GH. In my opinion, GH isn't so important provided you have both Mg and Ca and neither is at an extreme.

HTH
 

Tom Barr

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Jan 23, 2005
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Re: Nutri-Calculator

A simpler and more practical solution is to work with the plants here.

Take an assumption we can test for and have a pretty good relationship with: max NO3 uptake in a healthy thriving high light CO2 tank: maybe 4 ppm give or take a ppm or so. So 28ppm a week.


The ratio of N to Ca or Mg can be used based on the tissues of plants.

Adding 2 GH with an already balanced GH boosters, of Ca/Mg will facilitate any needs/demands and any excess Mg/Ca is not going to cause issues.

Some claimed so, so I tested it on said plant, nope.
Maybe I had a Mg2+ tolerant plant of the same species? :D

Extremely dountful........

Regards,
Tom Barr
 

Grafalski

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Feb 24, 2006
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Re: Nutri-Calculator

Czado. Thanks for your reply.
My tap water hardness is much higher. I didn`t check that yet but we get water from Lake Michigan in Chicago area. My RO water GH is 0 and when I mix it with my tap water (ratio 3 :1) I get 6 GH.
I also checked online water source info for my town. There`s no information about Ca or Mg level in the tap water. Water hardness is 137 mg/l or about 8 grains per gallon.
I`ve also seen Mg deficiency in my tank in the past and sometimes I see rusty wholes in anubias or cracks in Red Temple.
I was thinking about doing 50/50 mix (tap/RO) or just adding 1/4 of MgSo4 once/week. What results do you get when you do 50/50 mix?
 

Wet

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Re: Nutri-Calculator

Grafalski, I really like mixing 50/50 with my tap: keeps it easy and I do not see the issues some report. My primary reason is to drop my 5.5-6dKH tap since that tank is softwater -- this way I don't add dose anything different than my other tanks. I have stuff generally accepted as picky in there (Eriocaulon "Guang Zhou," R. wallichii, macrandra, etc), and I propograte and grow them fine. My issues in that tank are color, GW (it gets some sunlight), and 'scape. I don't attribute any of the problems to Mg or Ca.

When I dosed Ca without deficiency, my hope was the really long leaves of R. wallichii I've sometimes seen online from proponents of a Mg : Ca ratio, but I've since been told there's a variant called R. wallichii "Long leaves," and I wonder if the pics I've seen are of that plant. (I've dosed more Mg in the past as well, without noticeable difference.)

One day I may mess with GH Booster. I've just not observed the need to

Hope this helps.
 

JaSa

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NutriCalc looks like an excellent peace of software, but NutriCalc's tank calculator has one major error:
The definition of 1 litre is the volume of 1 cubic decimetre (10x10x10cm).
However NutriCalc's tank calculator calculates a 10x10x10cm to be of 0.9 litre. This error escalates for larger tanks, calculating 1 cubic metre to be 880 litres rather than 1000 as one would assume.
 

Tom Barr

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Hopefully it will be looked into and changed.

I personally never use the Calculators, I do individual determinations based on DI water and weighed dry compounds.

Regards,
Tom Barr
 

quenton

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Mar 14, 2006
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JaSa;11382 said:
NutriCalc looks like an excellent peace of software, but NutriCalc's tank calculator has one major error:
The definition of 1 litre is the volume of 1 cubic decimetre (10x10x10cm).
However NutriCalc's tank calculator calculates a 10x10x10cm to be of 0.9 litre. This error escalates for larger tanks, calculating 1 cubic metre to be 880 litres rather than 1000 as one would assume.

Hm -- wonder who did THAT -- oops -- that was me -- you are correct and I don't know why (yet). I will look at fix asap.
 

quenton

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Mar 14, 2006
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quenton;11403 said:
Hm -- wonder who did THAT -- oops -- that was me -- you are correct and I don't know why (yet). I will look at fix asap.

This a bit embarassing -- I had taken my conversion factors (out to about 8 decimal places) from my Palm Treo -- I have a 3rd party unit converter.

Seems the US-Gal to Litre conversion was 3.3xxx instead of 3.8xxx

I have now checked every conversion app against two web sites.

10x10x10 now gives 1.00 litres.

I have released V1.9 with that fix in it.
 

JaSa

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quenton;11407 said:
This a bit embarassing -- I had taken my conversion factors (out to about 8 decimal places) from my Palm Treo -- I have a 3rd party unit converter.

Seems the US-Gal to Litre conversion was 3.3xxx instead of 3.8xxx

Thought it was something like this. :D Been there and done that myself as I work as an IT-consultant. :eek:
 

quenton

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Mar 14, 2006
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Bartman;14579 said:
I tried downloading and installing the Nutri-Calculator today and I'm getting an error. It says

"This application has failed to start because MSVCR71.dll was not found."

Has anyone else had this problem or found a work-around for it?

I had at one point included that file with the install, but my latest release does not seem to have. I will do a new release, but cannot get to it until later tonight. If you want a quick fix, send me your email address via a private message and I will email you the file -- the .zip is 180Kb so I cannot attach it this reply.
 

quenton

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Mar 14, 2006
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Bartman;14579 said:
I tried downloading and installing the Nutri-Calculator today and I'm getting an error. It says

"This application has failed to start because MSVCR71.dll was not found."

Has anyone else had this problem or found a work-around for it?

OK -- new release is there. In fact the old release DID include that .dll, but
it seems it could not access it in the manner it was included. The new release
which is labelled as version 1.9.2 (as opposed to 1.9.1) puts the .dll in the
c:\Program Files\Nutri Calc
folder directly, which is what many other applications do to, in fact in doing
a search for that .dll, I found about 20 copies in various Program-Files folders.

Anyway -- hope that helps.

BTW -- I have been absent for quite some time. First I lost my big tank to
some disaster that sent it cloudy overnight, and killed 75% of the fish before
I got them moved to something else. Cloudy and almost a feel of geletin --
anyway, my other tank is still up but I have been out of things for a couple of
months due to hip replacement surgery -- my birthday present from my family
is to ressurect (sp?) my big tank so I hope to be back soon!
 

Tom Barr

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Hips before tanks, that's a good rule.
Hope you get better and the hip grows in well.

Regards,
Tom Barr
 
Thanks for the updated file! I’ll install it at home this evening.

I hope you and your hip are doing better. Did you ever figure out what happened to it to foul the water like that?

I'm sure getting it back up and running will make your recovery go faster and smoother.

You'll have to post a pic when it's back up and running. :)