Reduce KH

CoralNoobDude · Feb 1, 2021

Hello All,

I need the top ways to reduce KH that do not involve dosing. My KH currently is off the charts after I changed out some equipment on my tank, cleaned my filter and my fans. I added some RODI top off that i think might have been the culprit. During my initial fill of my top of bucket I accidentally filled it with straight tap. Fortunately I caught the mistake before adding that water to my tank, but I simply dumped that water and filled the bucket back up with RODI.

Anyway, I need to reduce my KH as I've noticed my Zoas have closed up really tight and angrily. Other water params below:

Ammonia < .5ppm
Nitrate < .20ppm
pH ~ 8 - 8.5
Phosphate < .2ppm
Calcium ~ 400ppm
dKH 12-14 --- HELP!!!!

lapin · Feb 1, 2021

Water change

CoralNoobDude · Feb 1, 2021

lapin said:
Water change

Would skimmer suffice...I so hate water changes. I've not had to do one for almost a year now....eck

lapin · Feb 1, 2021

hahahahahahaha

ZoaAddiction81 · Feb 1, 2021

Do you add any kind of p.h. buffer to your rodi water ?

Gtinnel · Feb 1, 2021

If un-willing to do a water change then IMO all you have left is to wait until something uses the alk to reduce it.
If doing a water change to correct a problem is too inconvenient then I suspect you've picked the wrong hobby.

Also adding rodi water without anything mixed into it will not increase alkalinity, so you may also want to figure out what you did to raise it to begin with.

Oregon Grown Reef · Feb 1, 2021

Do you have stony corals? If yes, then let them use it up. Are you dosing? If yes, then stop. Otherwise, raise your nitrates or do a water change.

CoralNoobDude · Feb 1, 2021

ZoaAddiction81 said:
Do you add any kind of p.h. buffer to your rodi water ?

I do not, is that needed?

ZoaAddiction81 · Feb 1, 2021

No I was just wondering if you were because that would raise the alk up way more.. What salt do you use ?

ZoaAddiction81 · Feb 1, 2021

What tester are you using for alkalinity ?

CoralNoobDude · Feb 1, 2021

ZoaAddiction81 said:
What tester are you using for alkalinity ?

I use reef crystals from instant Ocean, an API reef test kit and Hanna test kit.

ZoaAddiction81 said:
What tester are you using for alkalinity ?

oregongrownreef said:
Do you have stony corals? If yes, then let them use it up. Are you dosing? If yes, then stop. Otherwise, raise your nitrates or do a water change.

I never dose, I have a few stony corals. And water changing isn't inconvenient. It's just that I've not needed to do so for so long. and I only water change when parameters are way out of wack. So I guess this fits that description. Just hoping there was another option.

Oregon Grown Reef · Feb 1, 2021

Reef Crystals is your culprit. It's likely you've always had high alkalinity. The alk is usually in the 12-14 range depending on if you mix the bucket before using the salt.

CoralNoobDude · Feb 1, 2021

oregongrownreef said:
Reef Crystals is your culprit. It's likely you've always had high alkalinity. The alk is usually in the 12-14 range depending on if you mix the bucket before using the salt.

You're right! Just looked at the bag, I never paid attention to that, I just looked at the mix of all the other minerals it provides. So even a water change with this brand of salt will not assist. SMH. So back to the question of how to reduce it outside of water change. Or what brand of saltwater mix should I go after?

CoralNoobDude · Feb 1, 2021

Vinegar?

Oregon Grown Reef · Feb 1, 2021

Distilled white vinegar is one way to lower it.

Randy Holmes-Farley · Feb 2, 2021

No, vinegar is not a way to lower alkalinity. After it is eaten by bacteria, there is no net lowering of alkalinity.

Neither is soda water a way to lower alkalinity, despite one famous reefer touting it for years. Unfortunately, last I checked his false ideas were still around on the internet.

Randy Holmes-Farley · Feb 2, 2021

These are the best ways to drop alk in new salt water so you can do water changes with unusually low alk levels (or, if you want to live more one the edge, do it super slow in the tank: the issue is large pH lowering).
:

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

Muriatic acid?

Can I use this to lower ALK in freshly mixed saltwater.? Do I just add a little bit at a time and test until it gets to the level I would like it?

www.reef2reef.com

CoralNoobDude · Feb 4, 2021

Randy Holmes-Farley said:
These are the best ways to drop alk in new salt water so you can do water changes with unusually low alk levels (or, if you want to live more one the edge, do it super slow in the tank: the issue is large pH lowering).
:

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

Muriatic acid?

Can I use this to lower ALK in freshly mixed saltwater.? Do I just add a little bit at a time and test until it gets to the level I would like it?

www.reef2reef.com

Thank you, this definitely helps!

Oregon Grown Reef · Feb 4, 2021

Randy Holmes-Farley said:
No, vinegar is not a way to lower alkalinity. After it is eaten by bacteria, there is no net lowering of alkalinity.

Neither is soda water a way to lower alkalinity, despite one famous reefer touting it for years. Unfortunately, last I checked his false ideas were still around on the internet.

I knew something didn't sound right when I found that since it's added as a carbon source. It's the first thing that pops up on google though. I knew he was trying to do in tank, so I figured muriatic acid wasn't an option since it can be dangerous. Thank goodness you're here. Does vinegar has any effect in the short term on alk (ie. is it like rising nitrates that temporarily "remove" alk until nitrates are depleted through denitrification/algae)?

Randy Holmes-Farley · Feb 4, 2021

oregongrownreef said:
I knew something didn't sound right when I found that since it's added as a carbon source. It's the first thing that pops up on google though.

Your right, it does. That's ridiculous. I'll try writing to that site.

oregongrownreef said:
I knew something didn't sound right when I found that since it's added as a carbon source. It's the first thing that pops up on google though. I knew he was trying to do in tank, so I figured muriatic acid wasn't an option since it can be dangerous. Thank goodness you're here. Does vinegar has any effect in the short term on alk (ie. is it like rising nitrates that temporarily "remove" alk until nitrates are depleted through denitrification/algae)?

The measurable total alkalinity is reduced until something consumes the acetate, and then it comes back. That might only be hours.