Hardness, Alkalinity & ffff. (also pronounced: "pH&

[laserted]

Ever since switching to DI water, I've noticed a rise in the carbonate hardness of my tank makeup water. The first batches I used "proper ph 8.2" as a buffering stabilizer, since as we all know "DI water has no ph." (the accuracy of that statement has been dealt with in other threads!)

Anyways, due mostly, I'm sure to the buffering agent, my carbonate hardness has been quite high. As an example, Ca is +400, alk 2.9 meq and KH a staggering 19 degrees - all averages. I've discontinued the buffing agent's use for quite a while now, in a recommended attempt to "dilute" the KH / drop the hardness & alkalinity. Those values have been coming down S-L-O-W-L-Y, however, I'm now seeing a greater pH swing at nights - it's starting to dip lower than 8.0 (normal range 8.5 -> 8.2) Any ideas, and perhaps a better explanation of how the three are directly related? I'm aware that hardness affects alkalinity and alkalinity buffers against ph swings, but I haven't found the grail of "how to make your ph, alk and KH equal: ______"

Thanks,

Ted.

PS. Crushed coral sand on the bottom of a 40g reef, HSA-like skimmer, carbon monthly, co2 and kalk are currently off-line. DI by aqua-pharm's.

 

[Mike and Donna]

Try this:

pH and Alkalinity

 

[Adam1]

Ted,

I am highly suspect of your alkalinity readings. 2.9 mEq does not jive with 19 dKH. Myabe 9 dKH?

Ca of 400+ in newly mixed saltwater using a high quality brand is not outrageous.

I would verify both alkalinity test kits against a third kit.

HTH

adam

 

[Anonymous]

I just had to comment on your little "fff" thing. Very funny.

 

[jimmy n]

2.9 meq/l is a little lower than I like to keep my alkalinity and certainly does not equal 19 dkh.

I like to keep my alk between 3.5 meq/l and 4.0.

Jim