Good Question About Readings??

[Lambianz]

I guess when we take our Cal mag alk readings whether our tanks are different in gallon size doesn't make a difference on accurate readings?
We're only taking a portion of the water out to test. Besides actual monitor readings.
So 450ppm cal reading in a 10g nano is the same as 450ppm in a 300g tank? May be a dumb question on parts per million. This is definitely a question for the true chemist

[HighlandReefer]

When you compare identicle volumes of the water between the two tank sizes, yes they are equal if they have the same ppm reading when talking about the one ingredient in question. If you compare the total amount of calcium in a 100 gallon tank vs. a 10 gallon tank at the same ppm reading, then the 100 gallon tank will have 10X the amount of total calcium.

[Lambianz]

See it does make sense, because I made the mistake of shooting to much kalk in a syringe in my daughters tank to kill aiptasia, and the next morning her fish had died, of course from a ph spike. but it was no more of a treatment than I do in my total 90g system. So how do we make that calculation of 10X, being its 10x larger? than the 100g you mentioned? But how does that factor that if you have a 300g tank and its 500ppm cal readings that the same amount of cal dosing would or would not be the same in a 10g nano to get the same readings of 500ppm See I can't dose the same amount of kalk or mag or cal from one tank to another based on its water volume. So we don't overdose and kill something. Is there calculations somewhere to prevent this. Ooops to much kalk and the fish dies. Of course as mentioned, I have monitors to see quick what going on, on my system. It could be to late for those who don't.

[J. Montgomery]

<a href=showthread.php?s=&postid=14698044#post14698044 target=_blank>Originally posted</a> by Lambianz
So 450ppm cal reading in a 10g nano is the same as 450ppm in a 300g tank?
Yes, they're the same. You're measuring concentration of calcium, not the total amount. Concentration is mass per volume. A 300g tank would have 30x more total calcium than a 10g nano, but their concentrations can be exactly the same.

[HighlandReefer]

You can use the Reef Chemistry Calculator to determine how much alkalinity, calcium and magnesium to add to your size tank. Just enter in the actual total amount of water (not including sand and rocks) at the top first. :)

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

[HighlandReefer]

A word of caution. Kalk should be added slowly. Dripping kalk or using a dosing pump are my preferred methods. One should never add more kalk than what will raise your pH by 0.02 at one time. Kalk will also raise your alkalinity. Kalk is a balanced supplement for alk and calcium. :)

[HighlandReefer]

My above post should read that you should not raise your pH by more than 0.2 with each kalk dose. :rollface:

[steve9]

might want to keep alk higher in small tank ....i found that small tanks can drop very low quichly

[Lambianz]

Now steve9 has good info, why is that, and never seen the water gallon amount to add the right amount of additives to dose. I'll have to check it out. But when they say parts per million, ppm, that of course changes, because I read how everyone who test with test kits always have problems. And I do to with the ones I don't have monitors for.
Hmmm I wonder if I move my ph probe out of the fuge to the tank, if I'll get a different reading.