Alkalinity is WAY to high.

DON'T reduce it quickly, or you will do more damage than it being high. Lower it to normal levels over 18-24 hours with small water changes. I can't emphasize how important the bringing it down slowly is.

I would do 5 gallon or even smaller water changes. Even if you had 50 gallons of water (which due to the rock, sand, ect. you won't); 10 gallons is 20% of 50. That's a large water change. Maybe to a 5 gallon change tonight, another 5 gallon change in 6-7 hours, and then test alk. Then if it's still high do another water change in 6-8 hours. Bringing it down more slowly will help save most of your corals from dying from the sudden up and then downswing in alk. I would also check calcium, and be prepared to dose it as well. As alk goes up calcium precipitates out of the water, leaving alk very high and calcium very low.

Edited by CapnMorgan - November 02 2010 at 11:24pm

Welcome to the WMAS. Are you coming to the Mountain West Reef Fest on Saturday. I know several Idahoans that are.

Alkalinity of 20 dKH is not the only problem and Alk can be a little over 16 without causing problems. Have you re-tested to be sure 20 is correct?  You know, of course that there are two other Alkalinity scales, ppm and meq/l ? The acceptable Alk ranges are:
 8-14 dKH
 150-250 ppm
 3-5 meq/l

I would not rush out to do water changes without knowing the rest of the story.

Also, I disagree with the notion that Alkalinity should be reduced slowly. If Alk is this bad of a  problem, every minute that it stays high, is another minute of stress on the reef aquarium. It needs to be reduced to around 16 dKH and the sooner the better. Think of this example. You are outside this afternoon and it's sunny. It's nice and warm so you don't have a coat. Evening comes and the sun goes down, bringing on the cold. Within a few hours you are "freezing". Should you acclimate slowly over a few hours to a warmer place or should you go immediately into the house? This may be a little dramatic but hopefully illustrates the point. (BTW, This same example does not apply to pH, and to a lesser extent to water temperature. Each of those parameters has it's own characteristics.)

So what is the rest of the story?
What is the Calcium level?
Ca should always be checked too. Alk and Ca go hand in hand. Ca can be as high as 550 and as low as 350. If the Ca is below 400 ppm, I would simply add some Ca additive to help the Alk drop naturally without having to do water changes. If the Alk is really a problem, the addition of Ca will cause a small snowstorm in the water. This is a good thing in this kind of situation, because it chemically removes, by precipitation, whichever component is too high.

How did the Alk get that high? Was too much Alk additive used?

What salt mix is being used?
It's my opinion and experience, water changes are a common hobbyist action that sometimes do little to help and may even cause harm by masking the real problem. Lets look at it. A 10% water change should bring the Alk down by 10%, right? Well, if the change water had zero Alk that would be true and the new Alk would be 18 dKH. But change water does not have zero Alk. On average, salt mixes have an Alk of from 7 to 12 dKH. The true drop in Alk, if using Oceanic salt for instance, which has an Alk of 7-9 dKH would be about 1 dKH giving the tank a new reading of 19. It takes a lot of water changes to make much difference. That's a lot of bother in my opinion.

Hope this helps. My number is always below if you would like to hash it out quicker over the phone.
 


Edited by Mark Peterson - November 03 2010 at 6:08pm

The fish do looked stressed, also some hard coral has gone white = dead Im pretty sure.  I did a 5 gallon change last night, and I'll do 2 more tonight and then we will see where we are.  Thats all the fresh water I have.  Back to the store I guess.  The Calcium was 340 so I will dose some calcium.  And from what I can gather, there are two jugs of water here, one is for top off and one has tons of alk in it.  I think the alk one may have been used for top off by mistake.  Cant understand why it isn't marked, but that is another story.

Edited by Potgut - November 03 2010 at 2:55pm

Im sorry to hear about your loss :(