HELP! Alkalinity might be too high

[newbeemike]

HELPPPPPP! I noticed some of my hard coral are bleaching allittle bit. I know this is reversable so I checked everything in my tank and got the following:
Nitrite=0
Nitrate=0
PH=8.3-8.4
Here is where Iam concerned:
Alkalinity 17dkh (wayyyy to high)
Calcium almost 600. (Is there such thing as too much Calcium?not sure)
I think I been putting way too much Oceans Blend.

Obviously I need to back off on the Oceans Blend and do a Water Change tomorrow. Tank is 75 gallons. How much of a water change should I do. Any other advice. the fish seem fine no one is stressing yet. other coral seems fine ass well. But one acropora and a large pink birdsnest are bleaching (acro at the top, Pink Birds nest at the base coming up. HELPPPPPP Please.

[dustin_P74]

i would do atleast a 10% change. something close to 10 gallons

[NewbReefer]

i would do a 20g water to make sure to bring it down im not sure if theres a Alk down supplement. I know for PH there are PH down supplements for if your PH is to high.

[fatman]

As near to a 50 percent water change as you can handle and maybe do two water changes. The only other way to take down the alkalinity is with lots of carbon dioxide. Alaklinity is made up of a group of buffers. They react with acids so as to prevent a decrease in your pH. Co2 becomes carbonic acid which neutralizes buffers. Once your buffers buffering capacity is lowered the acid lowers your pH. However with that much alkalinity you woud be much better off removing most of the buffers rather than trying to neautrilize them. Much safer approach.

[ccCapt]

I would retest or have your lfs test you water. With both ca and alk that high I'm suprised you haven't had a precipitation snowstorm.

[Bifferwine]

If I were you, I'd start doing 10% water changes once a day or every other day until the parameters get back in check.

And in the future, don't dose anything unless you are simultaneously testing for it. Overdosing with additives is really easy to do.

[fatman]

Originally Posted by Bifferwine

If I were you, I'd start doing 10% water changes once a day or every other day until the parameters get back in check.

And in the future, don't dose anything unless you are simultaneously testing for it. Overdosing with additives is really easy to do.

Smart advice. It is often best also not to use mineral supplements that you can not test the levels of. Luckily you can test for alkalinity and calcium. Inbalances are easy to make and hard to correct, Ionic inbalance usually require lots of water changes to correct. Usually around 150 percent in water changes and that is with 25 percent water changes, takes even more total water with smaller water changes.

[ZOOT098]

you can also lower it by adding some unflavored carbonated water