# Water Change Calculator



## MOA (Aug 16, 2009)

hello,

This is a follow-up to my concejtures about water changes in general. I have made a spreadsheet that allows users to test several water-change scenarios based on their current data. Also, it allows users with contaminated water sources to see how beneficial/nonbeneficial particular water change schedules are. Moreover, this spreadsheet was inspired by TheAquaTools.com and is meant to be a general tool as well. Unlike many of my recent spreadsheets, it is an Excel 97-03 file and thus should be read by most programs.

http://sites.google.com/site/moashowmanyfish/why-are-water-changes-necessary/water-change-calculator

Please tell me what ya think,
MOA


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## Angel079 (Feb 14, 2007)

Hm that calculator you have linked to is really not impressing me.... if you were able to enter your stock/ tank size and it'll calculate that's do-able for anyone. But initial dirt amount in ppm and daily added dirt amount.....Not so helpful for the avg person I liked your other tools better then this one.


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## MOA (Aug 16, 2009)

Um, I think we got our wires crossed.

My calculator is the one at the bottom of the page: http://sites.google.com/site/moasho...alculator/waterchange1.xls?attredirects=0&d=1

The other one is the one that I was not impressed with either. Sorry about the confusion.

MOA


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## Angel079 (Feb 14, 2007)

I see what you mean now. I had used the link up top; I honestly didn't notice the fine print at the bottom where the actual Texas was kinda done already  Sorry but that


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## MOA (Aug 16, 2009)

No problem :-D No harm done.

Thanks for looking at it. What did ya think? Suggestions for improvement?

MOA


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## Angel079 (Feb 14, 2007)

What a question MOA how much of you stuff have I been reading now and like it 
And I can back up the way this calculates putting in my data for all current 5 tanks what I already knew was backed up again by this sheet; I could do less w/c. Which I actually recently started a discussion here and started doing my 55g every 2nd Sat rather then each Sat (no NO peaks nadda).

Edit: One thought coming to mind (which I think can't be done) it will not account for factors like heavily stocked or heavily planted tanks which does make a difference obvious (which is why I can get away with doing fewer w/c in the Jungle 55g)


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## MOA (Aug 16, 2009)

Hello Again,

Actually, it does account for the effects of plants, etc, but only in retrospect. That is, it creates daily rates of increase/decrease based on your old water change schedule and your current (normal) substance levels. Thus, it basically uses the following logic: If your aquarium normally has X amount of a substance and your previous water change schedule was Y, then your daily rate must be positive if the normal level exceeds the amount added by the tap water and the daily rate must be negative if your normal level is below the amount added by the tap water.

The net result is that you can not plug in something like "I want to add 20 plants," but you can buy the plants, complete a few water changes, and measure the result by plugging the new water test results into the spreadsheet. The differences in the daily rates will show the effect of the plants. No less, that is kinda tedious and...pointless.

As it stands now, the spreadsheet is designed to only handle the effect of changing your cleaning schedule, no more or less. Sorry for the inconvenience. :-(

MOA


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## 1077 (Apr 16, 2008)

My thinking leads me to believe for the average hobbyist, spread sheets are confusing. 
TDS meter would be much simpler to keep track of Total dissolved solids and or conductivity of the water if one was so inclined.


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## MOA (Aug 16, 2009)

1077,

Granted, but TDS meters and test kits cannot predict how changes to the cleaning schedule will affect such quantities. The ability to predict is where an understanding of the process, in detail, comes in. The spreadsheet is not really meant as a "do this"; it is meant as a "we now understand this." Make sense?

MOA


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## 1077 (Apr 16, 2008)

MOA said:


> 1077,
> 
> Granted, but TDS meters and test kits cannot predict how changes to the cleaning schedule will affect such quantities. The ability to predict is where an understanding of the process, in detail, comes in. The spreadsheet is not really meant as a "do this"; it is meant as a "we now understand this." Make sense?
> 
> MOA


 
Not particularly.
If one accepts that Total dissolved solids are comprised of everything in the aquarium capable of going into soluable form and that this can include By products of fish waste, and fish foods,, Then I would expect to measure a difference Before and after Water changes through Dilution of TDS and or TSS.
May not be able to predict how much of a change,,but I would hope the change would be for the better with regards to the fishes


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## MOA (Aug 16, 2009)

Um,

You're still talking about a retrospective model. However, the spreadsheet does account for the before/after differences. Not quite sure what you are getting at.

MOA


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## 1077 (Apr 16, 2008)

MOA said:


> Um,
> 
> You're still talking about a retrospective model. However, the spreadsheet does account for the before/after differences. Not quite sure what you are getting at.
> 
> MOA


Relax,, I'm on board with that which you have submitted.
Only disagree with your statement that TDS meters and or test kits cannot measure the effects of proper maint and water changes or a lack thereof ,,on Total dissolved solids,Total suspended solids,and or conductivity of a sample of water.
Been using such tools for a few decades
Everything that enters the glass box of water that we throw money, and or products into ,,from fish, fish waste,water conditioners,carbon, chemical media,buffers,fish foods,fertilizers,salts,medications,along with source water, contributes to Total dissolved solids or conductivity and or Total suspended solids, or at least that is my view. 
Can easily measure the (effects )of water changes and maint schedule ,or a lack thereof ,,, on reducing the levels of TDS ,or conductivity recorded ,,with the tools mentioned. Just need a notebook and a pen.


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## MOA (Aug 16, 2009)

My point exactly: such things can be measured (at least indirectly), but only after the change takes place. That is what I am saying; I am saying that it is good to examine methods that do not rely on after-effects.


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## 1077 (Apr 16, 2008)

MOA said:


> My point exactly: such things can be measured (at least indirectly), but only after the change takes place. That is what I am saying; I am saying that it is good to examine methods that do not rely on after-effects.


Agreed. Limiting that which goes into the aquarium is good preventitive measure ,and a measure I fully endorse as well as practice.
My apologies If I appeared unable to grasp your meaning. I am old.:|


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## MOA (Aug 16, 2009)

No worries. I know that you have a good head on your shoulders. I, on the other hand, have the tendency to bounce to absurd extremes. 

MOA


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