How to Lower Alkalinity? Is there a Product out there to Lower Alkalinity like you can with PH?

[Randy Holmes-Farley]

Is muriatic acid reef safe?

Muriatic acid and sodium bisulfate are reef safe (or I wouldn't be recommending them lol), but there is a big pH lowering effect as you lower alkalinity. That's why I usually recommend using them to lower alk in new salt water to very low (say, 2-4 dKH), and then do water change with them after aerating to remove the excess CO2.

But you can add them directly to a reef tank. DO it VERY slowly so the tank can blow off the excess CO2, and add it to a sump or other please where no creatures will encounter the acid before it disperses.

These have details:

Sodium Bisulfate to Reduce Alkalinity in New Salt Water or in Display Tanks

I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...

www.reef2reef.com

CHANGING SALT TO HAVE LOWER ALK.

I do water changes about every other week on my 50 display with 70-80 gal total system. I am currently using reef crystals and my alk. is testing at a constant 13 dkh. I would like to bring this down to around 8 or 9. what is the best way to switch salt mixes? I am thinking about redsea blue...

www.reef2reef.com

 

[Randy Holmes-Farley]

Water changes

Maybe. This thread is super old, but the alk in the OP's scenario likely came from his salt mix so I'm not sure how that will help him.

 

[MtnDewMan]

Maybe. This thread is super old, but the alk in the OP's scenario likely came from his salt mix so I'm not sure how that will help him.

I didn't realize the age of this thread or I probably wouldn't have posted. My point about water change was to 1) do a water change or set of water changes in case something was added in too much quantity to raise the Alk or 2) they were using salt that produced that high of Alk, which seems pretty high for many salts. If that were the case a set of water changes with lower producing Alk would help dramatically since the original poster mentioned the frag tank was just being set up. Much easier than adding tons of chemicals at this stage of the tank setup.

 

[Randy Holmes-Farley]

Much easier than adding tons of chemicals at this stage of the tank setup.

I think it is way more work (and cost) to lower alk by normal water change than to change much less water with even lower alk by adding a small amount of acid to it.