Switching ALK parameters due to salts being used

[metalmulisha]

Can anyone confirm wether or not they saw certain corals or coral or whole tank get affected based on slowly going to a higher or lower ALK? I say this cause pending on the salt you use they ALK can range from 8-12. I'm not talking about swings of alk and causing RTN but rather slowly coverting from a 8 to a 11 or opposite? I just went to a diffrent salt and went to a higher ALK and some SPS look crappy while others stayed the same. Thanks

 

[rburns24]

I think it mostly has to do with rapid changes in KH.
I've seen tanks with pretty low KH with great corals and I think it's because it's stable and it went down very gradually. I'm raising mine a bit, but doing it very slowly, as stability if the key for corals.

 

[clydog]

agree stability is key...i run at 7 dkh cause i use pellets

 

[Dr. Reef]

mix 1/2 and 1/2 of ur old salt and new to get a middle ground on alk. then slowly increase mor of ur new salt in the mix.

 

[metalmulisha]

mix 1/2 and 1/2 of ur old salt and new to get a middle ground on alk. then slowly increase mor of ur new salt in the mix.

Didn't think of that, thanks. I was gonna just change 20 gallons at a time (200 gallon tank) and use my gravity fed top off as a way of slowly dripping the new salt water in. So I'd take out 5 gallons at a time have it top off, then take another 5 out etc.... I think if I did that once or twice a week I should be good.

 

[Randy Holmes-Farley]

The alkalinity in a salt mix has almost no bearing whatsoever on the alkalinity in an established reef tank using that mix. With a day or two the alk will be determine by the amount you dose, not the starting values. Water changes generally have only a tiny impact on alkalinity.

For example, if the tank has alk at 8 dKH and the new salt water has alk at 11 dKH, a 10% change only brings the alk to 8.3 dKH. So that boosts alk by 0.3 dKH. Most people add 1-3 dKH per day in typical reef tanks, so that 0.3 dKH boost once in a while is not that significant.

 

[Haksar]

Thanks Randy for the clarification.

 

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing.