Attention (leebca) please

[hazeen]

Hi, would you please assist me to understand the following;

1- The PH should be within the range of 8.1 -8.4 , My tap water is 7.8 ( I will use my own RO/DI system), I don’t know what is the PH then will be ( still the system not arrive) higher or lower? , I’m affried that I need to adjust the PH, I have been told NOT to play with the PH as it will not be stable and it may suden drop down! And the substrate will take care of the PH level.. what do you think?

2- As mentioned in your table that:

Calcium - - - Alkalinity - - - - Magnesium
- (ppm) - - - dKH - meq/l - - - (ppm)
410 - - - - - - 7.0 - - 2.50 - - - - 1300

what I understand that IF the Calcium is 410 then the Alkalinity MUST be 7.0 and the Magnesium MUST be 1300. What if they are not in balance? shall I adjust each element Separately upon the PH reading? By the way, is alkalinity dKH is PH? I have no idea..if not then the above reading in your table should be on which PH level?

Thanks for your help

regards

[leebca]

Thanks for posting hazeen.

What that line from the table is saying is that for those three to be in balance, those are the numbers. Each number is determined by its own test kit. As directed in the section from which that table is listed, the adjustments are made slowly using chemicals you should be able to reasonablely obtain. If you go to the link given for the calculator, it tells you how much to add of the chemical you want. So like you write. If you start out with the Calcium at 410 ppm determined by the test kit, then the other two need to be those concentrations, as determined also by test kits.

You make the adjustments (ignoring the pH) based upon the test kit result. Do you have a titrating test kit for each, Calcium, Alkalinity, and Magnesium? One of the better makers of these test kits is Salifert.

The source water you use to replace evaporated water and to make up fresh salt water (unless you're using natural sea water), once treated and made nearly pure, can have a different pH. You don't have to worry about this, since when the Calcium, Alkalinity, and Magnesium are balanced and kept in balance, it will make the new water the right pH.

Focus on the balance and the pH will take care of itself.

Regarding substrate controlling the pH --- that is the old school way of thinking. It isn't true enough to help REALLY control the pH. What works is following the table and putting those three chemicals in balance. Once they are balanced, they will buffer the water and make it pH stable. You do not need nor do you want to buy and use pH adjusters, packaged buffers, etc.

Alkalinity dKH is NOT pH.

If the above isn't clear, or you need more info, just ask. I will be traveling today and not be available again until later.

[hazeen]

Thank you Master

I will follow what you have just said .. travel and back to us , wish you safe trip

now it is more clear to me. I will update you once you back

Take care and many thanks to you sir

[chrisfont23]

In addition to all Lee said, this is a super article that explains the relationship in detail. Lee, I am interested to see what u think about the part I pulled out below:

Chemistry And The Aquarium: Solving Calcium And Alkalinity Problems — Advanced Aquarist's Online Magazine
Alkalinity: 2.5 - 4 meq/L or 7 - 11 dKH or 125 - 200 ppm CaCO₃ equivalentsCalcium: 380 – 450 ppm calcium ion or 950 - 1125 ppm CaCO₃ equivalents
If you are anywhere within these ranges for both parameters, you do not need to perform any correction on your tank chemistry, though you may choose to do so for
other reasons. In this sense it makes no difference what the relationship is between the two values. If alkalinity is 4 meq/L, it is not inherently any “better” for calcium to be at 380 ppm or 450 ppm. Also, these ranges are somewhat arbitrary, especially at the high end. In fact, the primary reason for having a high end at all is that it is often difficult to keep one of these parameters above the minimum end of the range if the other is over the top end. So if one of these parameters is slightly above the high end, and the other is OK, that is not a problem worth worrying about.

[leebca]

Thanks chrisfont. I studied the chemical relationships and confirmed that which Dr. Randy Holmes-Farley has documented to be the closest to the actual chemical relationships. And after testing his chemical relationships in practice, subscribe to his article: A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com

The numbers in the table I have provided have been confirmed by chemists, other than myself. They are exact and variances in them do not yield as an effective chemical balance. We artificially raise the calcium levels because it is taken up by the marine life forms faster than we can replace it. So we operate on the high end. As Dr. Holmes-Farley has indicated in several articles (like the one you referenced) 'unless there is another reason' the ranges are okay. The 'other reason' in this case is to provide the excess of calcium in our captive environment.The numbers need to be held within the tolerance of the test kits to provide the strongest buffering ability, which are not that different from the ranges he suggests.

[chrisfont23]

The 'other reason' in this case is to provide the excess of calcium in our captive environment.The numbers need to be held within the tolerance of the test kits to provide the strongest buffering ability, which are not that different from the ranges he suggests.

That was my suspicion. But being a system engineer - which is no where close to a chemist/biologist - was reluctant to guess on a forum. Thanks Lee. I suspect you probably hear this once a day and it's early out here, so I'll be the first: you are awesome!