Maintaining Alk levels

[gregzz4]

Although I'm sure others may disagree with me ...
Ya, I can see how this is a concern for many, but doing a 50% change with 15dKH water into 7dKH will only net you 11dKH.
Although this may cause some shock to your corals, it won't kill anything healthy, IMHO ( the amount of Alk, Ca and Mag in the tank and the NSW are each devided by 2 )
These numbers, although a bit hi for the liking of some reefers, are not detrimental if they stay balanced with each other, and will eventually drop to your more comfortable levels
How many corals you have in your system, and coralline, will determine this drop rate

Many reefers have had to perform large water changes at some time, and I'll bet most would tell you that it, in itself, is not a major concern

I wouldn't, in your shoes, be overly worried about having to perform the occasional 25 - 50% WC in an emerg situation
It's just too much to bother worrying about, but is a great question

You may find ( until you have a large amount of corals and need to start dosing ) that you can control the exact params you'd like to keep by performing WCs

Thanks for the reply Greg. My ALK (Hanna) yesterday was 10.08 dKH and today is 9.184 dKH. Perhaps i'm letting it drop too low and well beyond dKH which is why it was STN on those SPS. I'm going to try to keep it steady for a while and we'll see what happens at the end of the week when its water change time.

Also just checked my calcium and it is at 440 ppm (Salifert).

[gregzz4]

Some like to run their alk over 11, but I've heard the best results are 7-9dKH

Your corals will tell you what they like best as they grow

^ Good advice, thanks.

I found the following info from Randy. It should be useful to anyone with this problem. He also addresses the ULNS question.
http://www.reefcentral.com/forums/sh....php?t=1993192

With my tank, I am dropping alkalinity by 1dKH each day. 3 days later, it is now at 7.6dKH so I just need to do maintenance doses and stick to smaller water changes of 10%. I think my STN occurred because my ALK probably dropped to 5dKH and then I did a large water change which raised it back to 10dKH.