Maintaining Alk levels

I'm using IO Reef Crystals. My ALK after a water change (30% weekly on a 24 gallon nano) always maintains at 10 dKH. Throughout the week, my ALK drops (SPS uptake and some carbon vodka dosing). Then at the end of the week, I do another water change which changes the ALk slightly. On my last water change, I noticed some STN from the base of several colonies, no burnt tips though. This appeared immediately after water change day. That was the only change I made. Yes I roll the dry salt bucket and let the mixture sit for 24 hrs at least.

Should I be maintaining my ALK according to the salt mix dose? That way when the water change happens, it does not increase dramatically.

I realize that a dKH of 7 - 9 would be ideal, but I find it too hard to manage keeping ALK at low level. I guess that means I can't go ULNS with this salt mix, or with a nano.

I'm dosing 0.01ml of vodka 3 times a week. But it is a barebottom tank and already at steady parameters ( 0 nitrate and <=3 phosphate).

[blacknife]

I think stability is the key. You could do smaller water changes twice a week, or start dosing to keep up your alk. Sodium Bi-carbonate which you can get bulk at many of our vendors, commonly known as baking soda. disolve some in ro water<a small daily batch or mix it bulk> figure out what your daily alk drop is and use one of the many calculators online to figure out what you need to keep it steady.

I think you can bake it in the oven to turn it into sodium carbonate which is more soluble in water making a stronger dose.

do some searches on 2 part dosing, I was only dosing alk at first, especially when i was using reef crystals<high ca> but once things got dialed in calcium needed to be added daily. You do not need a fancy dosing machine or anything that just makes it less work for you or the spouse. I just split my daily dosage into 2 and do it when I am feeding the fish.

I am using io right now and my alk is around 15 on a fresh batch but when only doing a 5-10 percent water change i just don't dose that day. I keep my alk around 7-7.5.

Thanks for the reply. I wish I could keep it at 7dKH and do a ULNS of probiotics or even VSV. Maybe when I upgrade to a larger tank. I do have auto dosers and ESV 2 part already. I just never had to use it on my nano.

What happens if you require a large water change of 30% to 50% in an emergency situation? Your ALK is currently at 7dKH, so would it then crash your tank as the salt mix is at 15dKH? I realize this doesn't happen often, but that would definitely increase your 7dKH to maybe 9dKH?

[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.