What Salt Do You Use

[horsehunter]

PG you have probably convinced me

Bert how do the 2parts raise salinity?

I skipped chemistry in school I was taking geometry in the pool room.

Frank

[PaintGuru]

I'm really not trying to "turn you to the dark side", just trying to explain to you why not many people test their salt going in, other than temperature and salinity.

[LongShot]

With the 2-part calcium supplements, the alkalinity component usually is mostly NaHCO3 and the calcium component is most often CaCL primarily. These 2 in combination eventually scew the ionic balance in favor of Na+ and Cl- over time, and will increase your salinity. If you're doing 10% or more water changes on a weekly basis, the effect is minimized, but it will show up eventually.

The problem I have with PaintGuru's logic,

[snip]
Say I do a 10% water change with water at 350 ppm. So that means the tank now has a calcium level of (0.9*400 + 0.1*350 = 395 ppm). Again, this is insignificant.
[snip]

is while this is very true for the isolated water change, if you continue to use a calcium poor salt mix you will drive your calcium down to it's "lowest common denominator".

Again, whether or not any of this has a significant effect on the long term success of any given reef tank is so dependent on such a wide variety of other factors (tank volume, husbandry practices, creatures hosted, bio-load, to name just a few) that it's impossible to say with any degree of certainty. Me, I like to aggravate myself with such things , and my critters have, over the years, shown some appreciation for the effort, so I continue to follow the same path. What'd be interesting would be to get another similar tank (hmmmm, there's an idea for pursuading my better half to tolerate that idea... "Honey, it's an EXPERIMENT" ), be a bit less "picky" and see what the results are.

Regards,
Bert

[PaintGuru]

Originally posted by LongShot
What'd be interesting would be to get another similar tank (hmmmm, there's an idea for pursuading my better half to tolerate that idea... "Honey, it's an EXPERIMENT" ), be a bit less "picky" and see what the results are.

I think you definitely need to get another tank....in the name of science .

[LongShot]

PG,

Can I count on you to help me convince she-who-must-be-obeyed of the worthyness of that endeavor?

Regards,
-B

[karlas]

used io but got red sea cheaper so i got that to try

ph 8.2
alk 10 dkh
calc 420- 425
phosphates 0

[tdwyatt]

Originally posted by horsehunter
...how do the 2parts raise salinity?

Frank, this is actually part of another thread that I am pasting here with links to related threads that will explain it in detail:

SG and salinity effect on alkalinity and reated readings

and a seemingly unrelated thread of total relevance

The last few posts in the second thread have links to Dr. Bingman's Aquarium Frontiers articles that fully discuss the effect Bart has described with 2 part additives. The 2 part additives are for the most part Calcium Chloride solution in one bottle, and Sodium bicarbonate/carbonate solution in the second bottle, usually in equimolar proportions per volume dose. Our corals use the calcium and the alkalinity part of these solutions, leaving behind... SODIUM AND CHLORIDE. Initially the only effect we see is an increase in SG due to the remaining sodium and chloride left behind after calcification by the corals, driving up salinity, but this is not the end of the story. With continued use, these elements build up in the water column, skewing the proportion of the conservative elements in our artificiakl seawater in favor of a sodium chloride brine. This occurs as we test the SG, see that it is a little high, and adjust the salinity (remove some of the seawater from the system and add FW to "drop" the salinity). As we continue to add the 2 part additives, more sodium and chloride goes in to the system, and the proportion of sodium and chloride in relation to the other elements slowly increases until the next salinity adjustment, and so on, untill the SG of the tank could theoretically depend almost totally on sodium and chloride alone, barely resembling seawater in any form.

This occurs more rapidly in systems that do not have regular 10% water changes, but will occur nonetheless in all systems that use 2 part additives as we know them now. Craig suggested at the Louisville-1999 MACNA meeting that folks that use such a Ca/Alk regimen perform regular 10% water changes every week to two weeks, and large water changes (on the scale of 50%) approximately once a year to reestablish the proportionality of the conservative elements.

A lot to consider, HTH.